Wednesday, November 27, 2013

Water manifold for a solar heater

Many people get the idea to heat water after attempting to drink from a hose that has been laying in the sun.  The water is hot so wouldn't it be easy to get a 100' of black irrigation tubing a coil it up. Yes this will heat water but there are problems involved with this method.

First is poor efficiency. As the water travels the length of the tube it begins to quickly gain heat, but the hotter it gets the slower it gains additional heat.  It would be better to use several short lengths to warm the water only as much as you need.  Adjusting the optimum length is more than I wish to get into, but with some experimentation you will find a range that suits your needs.

Another problem with one long coil is resistance to flow.  The longer you make the tube the slower the water will flow.  A manifold  can solve both these problems. Fabricating a manifold may appeal to some DIY folks, but hot tubs often use manifolds and so they are readily available for about $10.00
Water Manifold 2"S x 2"S (6) 3/4" Ports

It's been pointed out to me that a better choice would be CPVC due to the high temperatures these systems can reach especially when not in use and the water is not moving.

Flow Gaurd MultiPort CPVC Manifold

By using several short lengths you will increase the effective diameter and reduce the resistance as well as the demands on your pump.

Don't forget to use a high temperature water pump.  They are easy to find, but this is an important consideration that could be over looked.

Also the roof may look like an ideal place for a solar collector but you will have to have a pump tha can provide enough head pressure which will influence the cost of the pump and your choice of locations for the collector.

Tuesday, October 22, 2013

Your Local Grange

Until I read this story about the [California Grange being sued by the National Grange] I never gave a second thought to the Grange.  To me it was just a big building where they held square dances, but this article  [ What is the Grange?  ]  gives a much better description.

Gwen Schantz is chief operating officer of the Brooklyn Grange rooftop commercial farm in Long Island City, Queens.
According to this article, the California Grange has begun to attract "family sustainable farming".  I'm guessing we backyard gardeners might fit that description.   The California Grange has also taken a stance against GMO.
Rick Keel, a spokesman for the California State Grange recently said this “For lack of a better term, it seems to be ‘foodies’ who care about community today and see the Grange as a way to provide community service,”

"Since 1873 the California State Grange has championed the interests of farmers, ranchers, and rural Americans. The Grange stresses community service, and its Youth programs are open to all, urban and rural alike. There are over 185 chapters across the state.  For more information contact the California State Grange at (916) 454-5805. " - California Grange

With the Farm to Fork movement catching on; aquaponics and the local Grange may be a very good combination.   I'd like to encourage you to look into your local Grange for services.  It may take a while to bring the National Grange around to supporting sustainable farming, but it has to start somewhere.  The aquaponic and home gardening community have become forces of significant proportion.  I think we can make a difference.

If you are already a member I hope you will vote Ed Lutrell The National Grange Master out of office in November because he strongly supports GMO.

Sunday, October 13, 2013

Microbial Fuel Cell

On October 4th 2013 I began an experimenting with Microbial Fuel Cells.   My initial experiment consisted of a piece of carbon fiber cloth 36” x 4” which I placed in the water of my aquaponic system.  The bacteria grew on this cloth.  After nine days  I measured the voltage at .97 millivolt (mv) using a stainless steel cathode of approximately 6"x8" .

While there are some similarities Microbial Fuel Cells are not the same as a BEAMR (BioElectrochemically Assisted Microbial Reactor) which is basically a Hydroxy gas generator.   

Several years ago I was very involved with the creation of Hydroxy gas.  Commonly known as HHO or Browns Gas.  By using electrolysis and electrolyte such as KOH (Potassium Hydroxide)  water is separated into hydrogen (H2) and oxygen (O2) in a 2:1 molar ratio.  These two gases violently wish to be reunited and all it takes is a spark.  This gas has some good applications, but it requires more power to create the hydroxy gas than the gas will return as a fuel source.  Some people have found benefit when injected along with fuel into engines that do not have
I mention this because you may find this technique while researching Microbial Fuel Cells and fall victim to the misguided ideas surrounding the creation of hydroxy gas.  

Microbial Fuel Cells are batteries created by the energy produced by the bacteria.  I can't say it any better than what has been written on Wikipedia so I will quote the entire first paragraph.

"A microbial fuel cell (MFC) or biological fuel cell is a bio-electrochemical system that drives a current by mimicking bacterial interactions found in nature. MFCs can be grouped into two general categories, those that use a mediator and those that are mediator-less. The first MFCs, demonstrated in the early 20th century, used a mediator, this is a chemical that transfers electrons from the bacteria in the cell to the anode. Mediator-less MFCs are a more recent development dating to the 1970s; in this type of MFC bacteria in mediator-less MFCs typically have electrochemically active redox proteins such as cytochromes on their outer membrane that can transfer electrons directly to the anode.[1] Since the turn of the 21st century MFCs have started to find a commercial use in the treatment of wastewate"

A little more research indicates that a MFC (Microbial Fuel Cell) must use anaerobic conditions. In aerobic conditions bacteria are free to use near by oxygen for the electron they wish to transfer. The anaerobic condition leaves only the cathode exposed to available electrons from oxygen. This creates the electrical difference between the anode and the cathode.

But I did measure a very small voltage of  97 mv on Oct 12 2013, so maybe maybe the process would be better in an anaerobic condition, but still prove viable in aerobic conditions. I'll come back to this in a few weeks and post the results.  It may improve as the bacteria continues to grow on the cloth.

It was just two days ago that I measured 97 mv... I tested the voltage again today Oct 14 2013 and found that if I moved the cathode closer to the anode I could get 300 mv!

Weedponic Garden

Many people are growing with hydroponics and aquaponics because they wish to reduce their water consumption,  eat healthy organic food,  live in a more sustainable way, and reduce the carbon foot print of their existence.

Soil based gardening has become dependent upon outside resources but Aquaponics is even more reliant.    Some of those resources are affordable only because fossil fuels are still available.  If those resources were not available how would you feed your fish?  How would you supply nutrients such as iron, calcium, potassium, phosphorous and magnesium.

Aquaponics has good intentions, but it is not a sustainable agricultural method.  I currently do not have all the answers, but I'm working on it. Here are some options and food for thought

I'll start by defining the problems.   Fish food is made from grains and wild caught fish comprised mostly of fish with little commercial value, and processing waste. But the fishing industry is not sustainable, and much of the grain used to produce fish food is GMO;  raised using large amounts of fossil fuels for fertilizer and machinery in order to produce a profit while neglecting the environment. For more about the analysis of fish food read
The result is that similar to feeding cattle enormous amounts of gain are used to produce a small amount of meat.  

But we don't need to feed our fish commercially produced fish food.

David Epstein at Bioponica has been feeding his fish only vegetable matter.  This is a great way to avoid dependance upon fish food.

Live food such as Black Soldier Fly larvae, fly maggots, worms, and other insects are also good sources of protein.

But do we even need fish?  If you are like me an only eat fish a few times per year, maybe you will consider bioponics which replaces fish and fish food with humonia.  Bioponics is hydroponics using readily available urine rather than fertilizers made with fossil fuels.

Humonia (aged urine) is a strong source of nitrogen and potassium plus it provides many other trace minerals.   I have been growing with nothing but humonia, epsom salts and Fe-DTPA for quite a while, and I like the freedom it allows.  Humonia will always be available, but iron and magnesium are still missing and a bit more difficult to make at home.

I personally have no problem using humonia for a nutrient source in a bioponic garden.  Human urine shouldn't contain pathogens or bacteria if you are healthy.  Aged urine turns to ammonia.  But I get that some people would prefer not to collect their urine, or use it anywhere near a vegetable garden.  So I have been exploring various avenues to find a source of nutrients.

What if you could grow vegetables without any animal input including humonia.  Similar to David Epstein's plant matter for fish food; bags of plant matter can provide nearly everything a garden will need.  For example coffee grounds can provide the following.
Nitrogen: 2.28 percent
Phosphorus: 0.06 percent
Potassium: 0.6 percent

A little more research turned up these sources of nutrients:
Weed/Herb Tea
    Nettles, comfrey, yellow dock, burdock, horsetail and chickweed - Potassium
Cornmeal - phosphorus and nitrogen
Molasses  – [ acts as a chelate[Calcium,Magnesium,Potassium,Iron]
Banana - potassium
Coffee Grounds -  phosphorus, potassium, magnesium, copper, sodium and chloride
Egg Shells - 93% calcium carbonate
Seaweed – trace elements
Manure – nitrogen
Grass Clippings – nitrogen
Humonia –  nitrogen, phosphorous and potassium
Wood Ash - calcium  and potassium
Epsom Salts - magnesium and sulfur
Fish-Emulsion - nitrogen, potassium, phosphorous, and amino acids

Vermicompost -
  • • Organic Carbon 20.43 – 30.31 %
  • • Nitrogen 1.80 – 2.05 %
  • • Phosphorus 1.32 – 1.93 %
  • • Potassium 1.28 – 1.50 %
  • • Carbon : Nitrogen 14-15 : 1 %
  • • Calcium 3.0 – 4.5 %
  • • Magnesium 0.4 – 0.7 %
  • • Sodium 0.02 – 0.30 %
  • • Sulphur Traces to 0.40 %
  • • Iron 0.3 – 0.7 %
  • • Zinc 0.028 – 0.036 %
  • • Manganese Traces to 0.40 %
  • • Copper 0.0027 – 0.0123 %
  • • Boron 0.0034 – 0.0075 %
  • • Aluminium Traces to 0.071 %
  • • Cobalt, Molybdenum Present in available form
Grass clippings - Over 3 days the Ammonia increases significantly  Plenty of Phosphate too
Soaking grass clippings for 3 days produced a lot of ammonia and phosphate

The iron in vermicompost and planting nitrifying legumes are the only sources I've found. Tests will have to be done.   I have yet to grow a garden this way but it appears a lot will be learned when I do.  Perhaps you too will set up an experimental Weedsponic Garden and let me know your results.

Wicked Beds

A look at the construction of my Earthan Beds. Previously these beds were Wicking Beds with sand in the bottom, but now I want to be able to let aquaponic water flow freely through the beds so I've replaced the sand with rocks. The soil I place back into the Earthan Beds is a mix of sand, compost, pumice, and garden soil, amended with Azomite. Pumice is not required, but it provides plenty of surface area for bacteria while making the soil light and airy. When I first started to use my wicking beds I noticed the smell of anaerobic bacteria. By allowing some water to flow out of the overflow tube each day I was able to prevent this anaerobic condition. When I removed the sand and soil from the wicking beds I found no sign of anaerobic bacteria. By letting the water flow through the Earthan Beds I will create a good environment for nitrification and prevent anaerobic conditions. The water from the Bioponic System will also provide nitrates and other elements for good plant growth.

The first video shows how I constructed the Earthan Beds

This video starts out with a tour of my fall garden.  
Click the hot spot to skip ahead to the nearly finished wicking beds.

Saturday, October 12, 2013

Duckweed and String Algae

The video above is one of the best for both duckweed and string algae.

String Algae may begin to grow in your system.  It's not all bad because it can be useful as a fish food, but it tends to clog the system.  If your fish don't keep it under control a small amount of salt in the water will kill the string algae.

There are many varieties of duckweed.  I have two, but one or the other will tend to prevail depending on the time of year.  Duckweed can be rinsed and used in salads and it provides good protein for your fish.    Under ideal conditions duckweed will double it's volume in just a few days, but you will probably have to raise your duckweed separate from your fish because they will eat it faster than it reproduces.

Duckweed cleans the water, but it can also exclude oxygen if it grows too thick.  It prefers warm water, and seems to grow out of control when the conditions are right.  Creating the right conditions can be difficult, so I spread it around various areas and let it grow where it wants to grow. 

Good article about Duck Weed

Saturday, October 5, 2013

Monday, September 16, 2013

A Handbook For Aquaponics

Gardening with aquaponics is a passion for me.  For almost 2 years I've visited my fish first thing in the morning, and it's the last thing I do before bed.  I enjoy the science and systems that sustain this marvelous symbiotic garden with biological interactions that continue to flourish and amaze me.

I'll warn you that a lot of what you will find on the internet is hype and rubbish.  For example growing lettuce at four times the normal yield is just not going to happen. Aquaponics is not going to feed the world, and it's not as easy as many make it look, and unless you are a top notch salesman you will not grow rich selling produce, and fish or aquaponic systems. Beware of people selling anything related to aquaponics. There are no secrets in aquaponics.

Why do you want to grow with aquaponics?  Chances are you either want to
1. save money on food,
2. avoid kneeling,
3. reduce your water consumption,
4. be sure you are eating healthy organic food,
5. help reduce the depletion of fossil fuel and lower the carbon foot print of your existence.

Maybe it's all of these, but "traditional aquaponics" is not a sustainable method. To be fair, I can't think of any method of farming that provides animal protein in a sustainable fashion, especially if we are not able to allow the animal to free roam and forage for their own food. After you add up all the energy involved with aquaponics it still uses more energy to pump water than the caloric energy it grows. But aquaponics is a move in the right direction, and it does save transportation energy. In ideal locations aquaponics could produce 30,000 lbs of fish per acre per year compared to less than 100 lbs for cattle, but don't forget the fossil fuel required to make that happen. For more on that [CLICK HERE].

As a side note, farming in general tends to be wasteful.  400 gallons of oil is used annually to feed  EACH modern human.  34% for manufacture of inorganic fertilizer.  19% for operation of field machinery. 16% for transportation long distance.  By growing in our back yards with free nutrient rich sources which I will tell you about later.  We can save a lot of oil, but we need to be conscious of our own waste.  Pumps, heaters and lights use energy.

This is why I strive to design low energy systems, and grow with the seasons. These integrated systems qualify as Permaculture, and I will show you how to accomplish every one of the goal on that list! My first rule is don't fight Mother Nature. She can be generous if you work with her.

Traditional aquaponics may never grow enough food to get back what you invest, but you will save a lot of water, know first hand how safe your food is, and if you design it with raised beds or vertical towers you will not have to get down on your knees.

Growing a garden is a challenge, at least it was to me. Aquaponics is not any easier, and often times more difficult than soil based gardening. I don't consider myself an expert, just experienced. I hope I can help you get you off to a good start because it can provide a great deal of enjoyment.

Here is a list of topics I will cover

Water Quality
Carbonates, pH, water chemistry and nutrients
Media beds
Radial Filters
Cycling & Nitrification
The System Build
    Wood Tanks
    International Bulk Containers (IBC)
    Bell Siphons
    Timed Fill and Drain
    Old School Fill & Drain
    Air Pumps
    Airlift Pumps
    Electric Pumps
CHOP 1 vs CHOP 2
Level Systems
Flow Rate

    Compassionate Killing of Fish
     Fish Food
    Breeding Fish
Level Systems
Media Beds
    Wicking beds
    Earthan Beds
Wicking Pots
Deep Water Culture (DWC)
NFT (Nutrient Film Technech)
Vertical Towers 
Green Houses
    Rocket Mass Stoves
    Evaporative Coolers
    Pipe sizes
Starting from Seeds
Keep a Log
Sea Salt
Pest Control
Site & Experts to follow

I want to talk about the many questions I had as a newbie aquapon, and discuss some brilliant ways to improve traditional aquaponics.

Questions will always come up when designing your first system. I will attempt to remember what mine were, and anticipate what yours are too. I also want to mention an alternative to aquaponics with fish. Bioponics is aquaponics without fish. It uses other sources of nitrogen there by avoiding many problems and expenses involved with raising fish. If you do not eat a lot of fish I encourage you to go this route.

Water Quality
There are often concerns about detritus in the media and water. Let me first say, worms in all of your media beds are very beneficial whether it be Earthan, Wicking, or LECA (Lightweight Expanded Clay Aggregate). They consume dead roots, uneaten food, and with the help of bacteria in their guts, make minerals available to the plants through a process called chelation. They help keep the media clear of excess gunk, and feed the plants in the process. Worms (Eisenia Foetida – the Red Wiggler, Californian red worm) to be exact should be in your system. You can even feed them to your fish.

Carbonates are bad for beginning systems because they remove a level of control for beginning systems (i.e. before your nitrification efficiency is up). Your related acidification is really weak and carbonates can overwhelm the process, leading to chronically high pH. (i.e. 8+) which limits nutrient availability and makes it difficult to stabilize your system where it should be (below 7 for commercial systems). - Nate Storey (Bright Agrotech)

pH and water chemistry and nutrients:
If the pH gets too high you will need to lower with acid.  Buffing from the carbonates in your grow media, and local water supply may make the pH difficult to adjust.
At the point at where the buffer is overcome any further amount of acid will cause a drastic pH change
GO SLOW.  As you add Hydrochloric acid the pH will drop, and then bounce back.  Don't get frustrated and dump extra in.  You will reach a point where it kicks in and then a little goes a long way. It is possible to kill your nitrifying bacteria if you go too low.
I've never had a problem with low pH, but the same applies.  Add a threshold level of HCl (Hydrochloric Acid) or KOH (Potassium Hydroxide) and then test pH a day later and adjust with a smaller adjustment dose.  This is actually safer than calculating because it allows other variables to impact pH over the course of 24 hrs.

Some people like to keep pH adjusted water on hand.  Rain water can also be used to avoid adding calcium bicarbonate when topping off the system. 

A Reverse Osmosis (RO) system removes calcium bicarbonate from the water.  They are expensive but they eliminate the constant struggle many find when striving to maintain a perfect pH. 

Iron is almost always lacking in aquaponic systems.  The form of iron is very important. The three common chelated forms (iron-EDDHA, DTPA and EDTA) differ in their ability to keep iron soluble and available to plants as the pH increases. Between a pH of 4.0 to 5.5, any form of iron will work (including iron sulfate) at supplying iron to the plant. However, as the pH increases above 7.0, only the iron from Fe-EDDHA will have high solubility. Iron-EDDHA 4 >< 9 Iron-DTPA 4 >< 6.5 Iron-EDTA 4 >< 5.5 Research has shown that the ranking of iron forms from most effective to least effective at supplying iron at high media pH is Fe-EDDHA Iron-DTPA > Iron-EDTA > Iron sulfate. If iron is applied in a form that is not soluble because of high media pH, then most of the nutrient will not be available to plants until media pH is lowered.
In general the best products will say EDDHA (Sequestrene 138) because they work over the widest range of pH. Sequestrene 330 is ETPA and it is more affordable. Use Sequestrene 138 only if your media is alkaline and calcareous If your soil/media is very acidic I would still use ETPA Sequestrene 330 rather than EDTA. ETPA (Sequestrene 330) is the best all around iron to buy if your are maintaining your system between 6.2 and 6.5. Iron Sulfate can be used as a foliar application in aquaponics, and may not be terribly detrimental to your fish, but I would not use it when there are better choices.
Sequestrene is what I use and it's widely available on the internet, but others are good too. Sequestrene 138 may has been reported to turn the water red but I've only used 330 so I don't know for sure if that is true or how much of a problem it is.

Media beds clean, and filter the water, but that is not their primary purpose.  In fact even a bio-ponic system (aquaponic system without fish)  will accumulate muck in the media.  To a certain extent that is what you want for good nitrification and as your system matures it will continue to improve.  What you don't want is food and poo clogging the media, and creating anaerobic spots.  Therefore we remove the detritus from the water with a radial filter.  The main purpose of media is to provide nitrification, and as luck would have it, media beds provide a place to grow plants.  People from the aquaculture world often miss this last point and try to incorporate a very efficient Fluidized Biological Filters as well. 
The primary focus of aquaponics is plant growth and fluidized filters also known as moving bed filters create no space for plants, but there are situations where they may be useful.  For example you may wish to have more fish and have no room for more garden beds.

Media provides filtration, a place for plants and most importantly nitrification.

BSA (Biological Surface Area) depends upon the SSA (Specific Surface Area) of the media.  The higher the BSA the better because the bacteria which provides nitrification likes to grow on surfaces.  Most IBC systems average about 25 ft2 surface area per pound of fish.  100 or more sq ft per pound would be really great for the fish, but somewhere in this range is good.

The surface area of the media where the bacteria grow increases with porous media.  Kaldness is used in aquariums because it has been designed to provide a very high SSA of about  244 ft2/ft3, while providing good flow.  Flow is the crux, because even though media such as sand has a high SSA of about 270 ft2/ft3. and a void ratio of about 40% the flow rate is too slow.

There is a wide range of media with good flow and high SSA,  but some to stay away from are any rock that will change the pH such as marble or lime stone and GrowStones in apquaponic systems because they are made of glass which will leach into the fish tank and harm your fish.  They would be great in a bioponic system though.

The best products are LECA (Lightweight Expanded Clay Aggregate),  Expanded Shale or Bio-Char if you are able to afford, and obtain them.  For the rest of us Lava Rock is my preference because it is cheap, porous, not too heavy and contain a lot of minerals for the plants. Microporous solids called zeolites form in volcanic rocks.  According to Russel Water Gardens - Lava Rock has an SSA of 86 ft2/ft3 and a bed porosity of 20%

For comparison I found this reference
gravel (40–70 mm,specific surface area of 700 m 2  /  m 3 and bed porosity of 0.4)and a LECA with the commercial name of Filtralite NR(4–8 mm, specific surface area of 1250 m 2  /  m 3 and bedporosity of 0.45).
I converted that to inches and feet.
1.5-2.5 inch gravel has an SSA of 213 ft2/ft3 and bed porosity of 40%
1/8–3/8 inch LECA has an SSA of 318 ft2/ft3 and bed porosity of 45%).

Some of these figures do not seem to jive...  It may be that the 2' gravel was not ordinary drain rock.

Nate Storie showing specifications for Sand, Pea Gravel, 3/4" Rock, 1" River Rock and his Zip Tower Media

Radial Filters are inexpensive to build, extremely efficient, and offer the side benefit of capturing fry before they are eaten. To grow healthy plants we must keep the roots clean, and the radial filter will do a better job. There are many versions of radial filters on the internet, but the principal is pretty basic, and easy to understand. A radial filter will remove most of the detritus by slowing the water down, and allowing it to settle to the bottom of the radial filter, thus keeping your DWC raft beds, and media beds as clean as they need to be.

Basic radial filter
There have been quite a few other types of filters tested, but any attempt to use filter pads will create a lot of extra work, and jeopardize the clear flow of water if you forget to clean it. Depending on the size of your filter you will be married to that chore more often than you like.

I only do this when my fish have babies, but occasionally I will place a filter inside my radial filter on the exit pipe in order to save the fry that get sucked in. I can then move them to a safe tank until they grow a bit larger.

One of the biggest blunders newbies make is to buy fish before the system is cycled.  Cycling involves growing bacterial (nitrification) which will naturally find their way into a aquaponic system.  There is no need to buy this bacteria, and every product I have ever used did absolutely nothing.  This includes products claiming to have several bacteria strains, and those claiming to have special enzymes.  Nitrification takes a minimum of three weeks, and as your system ages this process will mature and get even better.
There is only one way to speed the process.  You can obtain a fresh bucket of media from an established system and add it to yours.  Water from an established system will not work.  To feed and grow the nitrifying  bacteria simply add enough urine to maintain the ammonia at about 0.5 - 1.00 ppm more or less, and let the water flow through the media and it will begin to grow.
There is possibly one other way to quickly establish nitrification, but I have never tried this.

Nitrifying bacteria live on surfaces therefore a high  BSA is good.  Nitrification is a process where bacteria convert ammonia to nitrite and other bacteria convert nitrite to nitrate.  This is a two-step oxidation process of ammonium (NH4+ or ammonia NH3) to nitrite (NO2-) then to nitrate (NO3-) .  During the cycling process do not adjust your pH unless it falls below pH 7.  The bacteria prefer a higher pH.  The pH can be adjusted later when the bacteria have become established.  It is this nitrification process that removes the ammonia and nitrites from the water and creates a clean healthy environment for your fish.  Without it you will be doing several water changes per day of burying dead fish.

Nitrogen is a key component of aquaponics.

The United States uses about 13 Million Tons of nitrogen fertilizer a year.  It takes  liters of fossil fuel to make just  2.2 lbs or 1 Kg of nitrogen, so alternative sources is a big deal and I hope I can convince you to use sources of nitrogen such as urine and weeds which are simply going to waste.

We add protein in the form of fish food and that breaks down into nitrogen for our plants.  For most of us this is all we need to know, but if you wish to crunch numbers and maximize the use of nitrogen then I suggest Commercial System Design – Nitrogen Budget. Paul Van der Wolf explains the entire cycle in depth. 

The System Build
Your first system will probably be done as inexpensively as possible, and you may be temped to try some of your own ideas. I can tell you from experience that your tanks need to be sturdy, thin enough to accept a Uniseal or bulkhead, and of a material that will not rot from constant exposure to water which I guarantee you will spill plenty.
Concrete may seem like a good choice, but only if it is sealed. The problem with concrete is that it will affect the pH and if you continually force the pH down to an acceptable level the concrete will also weaken and crumble. There are ways to seal it with pool paint or wax, but it's is probably better the just avoid it.

Wood Tanks will rot if water accidentally gets under the liner. I have successfully [built wood tanks using fiberglass], but in the end this was more expensive than a good solid agriculture stock tank which can generally be picked up for about $1/gallon.  Over time the bulkheads tended to loosen - probably due to the contraction and expansion of the wood.
These bunk feeders make good DWC Raft beds and the stock tanks are perfect for fish tanks
The advantage to building your own tanks is you get to make them exactly the size and shape you wish.

International Bulk Containers (IBC) and plastic drums also make very good tanks, and the size is appropriate to most backyard systems. But I like a fish tank that I can reach my hand to the bottom of so you may want to cut your container down just a little.

Drums are often free, so it is an ideal way to start. Some people like them well enough to stay with them. I like the way Justin has built his grow bed using 1/2 drums because there is no frame below the drums, but I would have added a support leg in the center or used 2x12. By the way a barrel has a removable lid a drum has two bungs.

Bell Siphons work while the flow remains within the parameters they were designed for, and as soon as something changes they will fail. As much as I enjoy listening to a bell siphon cycle through it's phases; and even though I'm the guy who came up with the idea to use a small reservoir at the end of a breather tube, I will never use another bell siphon on any system I build. The reservoir helps, but it's a Band-aid fix. Why bother with a bell siphon when there are better solutions.

Timed Fill and Drain are a better choice and they conserve energy. Running a 100W pump 24/7 uses 2.4KW per day 365 days a year. A 15 minutes on 4 hours off cycle consumes 16 times less power than a continuous run bell siphon system! I do not believe turning a pump on and off shortens the life of a pump, but everyone can have an opinion.

Media beds traditionally use a Bell Siphon, but a Timed Fill and Drain system will use less energy and run with far fewer problems.

Timed Fill and Drain systems use a small weep hole which allows the media beds to drain more slowly than they are filled. A stand pipe allows any excess water to overflow back into the sump tank until a timer turns the pump off. The beds are filled several times a day, and when the pump shuts off, the water weeps out and drains the media bed.

Old School Fill & Drain
I don't know if this siphon valve has a name or how well it works, but I first saw it in Travis Hughey's Barrel-Ponic Manual. It works by pulling a toilet flapper with the weight of a 2 litter bottle. Just giving you all the options.

Air Pumps
I'm running my air pump to 9 air stones and moving over 1000 gpm with 2 airlifts. I'm using all the air (200 lpm) my Eco Plus 7 compressor can deliver. It runs at 93W wide open and 51W when closed.
The specs say an Eco Plus 7 compressor is rated at 200 lpm 5.1 psi and 280W. I believe the 280W rating refers to the maximum heat dissipation the motor coils can endure. I've rebuilt Active Aqua air pumps and I've looked inside this Eco Plus 7 and found the Active Aqua to have less space within the enclosure. After I could no longer rebuild my Active Aqua I bought the Eco Plus. My feeling is that Eco Plus has created a larger cooling area that allows the pump to operate much cooler and last longer. I could not pick my Active Aqua 70 lpm up with bare hands whereas the Eco Plus 200 lpm is only warm.

I've done a similar test with my Ametek Rotron EG DR083 regenerative blower and found that restricting the outflow increases the Wattage, contrary to the compressor. The regenerative blower is great for air stones where the depth is usually pretty shallow. It delivers 521 liters per minute and uses just 118W, but the compressor's advantage is the ability to deliver 5.1 psi. The regenerative blower has only 0.867 psi. So the regenerative blower does not work well for airlift pumps but it blows a hell of a lot of air to air stones!

Airlift Pumps 
Air stones are highly recommended throughout any system and since we are running an air pump why not utilize it for pumping water too? That's right airlift pumps will move large quantities of water on less power, and aerate the water while doing so.

One of the really nice things about airlift pumps is the way they can pass solids without clogging. They are in my opinion far more reliable than centrifugal pumps, and a whole lot less expensive. My airlift can be built for less then $10 and it delivers over 1000gph.

Electric Pumps - If you purchase an electric pump there are some considerations. To keep this paper short (lol) I'll insert a [Link Here]

CHOP 1 vs CHOP 2
CHOP (Constant Height One Pump) Traditional Aquaponics uses either a CHOP 1 or a CHOP 2 design. The water level in the fish tank is always a constant height and one pump delivers water to the fish tank which overflows into the media beds and then back to the sump tank. Chop 2 differs by one pump delivering water to both the fish tank and the media beds. These each return water back to the sump tank. The advantage of CHOP 1 is greater flow through the fish tank. The advantage of CHOP 2 is the ability to isolate the media beds and the fish tank. These traditional systems aerate the water by drawing air down through the media each time the water level fills and drains.

Level Systems
There seems to be some misconception that fill and drain action is required for good aeration.  This is simply not true.  There are several methods to aerate water.   

Air stones, with an air pump are generally used in any type of aquaponic system  I highly recommend many air stones throughout the system, and air lift pumps definitely ensure good aeration.

Level systems do not waste energy lifting water from a sump tank.  Instead the water is simply pushed along through the system, remaining the same height from one section to the next.  The air lift pump, and air stones provide all the aeration necessary for good healthy roots.

This of course does leave the roots sitting in water in the media beds, but so do raft systems.  There may be a few plants that don't appreciate constantly wet roots, but most do fine.   Media beds have been included in every successful aquaponics system since day one,  but a new concept has evolved which integrates wicking beds with aquaponics.  It's called Earthan Beds, and I'll tell you more about that later.

Flow Rate - Kieth Tatjana recommends twice per hour, but no more. The Aquaponic Gardening Community site recommends once per hour. So if you have a 100 gallon fish tank you should pump 100 to 200 gallons per hour. These rules of thumb are good enough, but if you are designing a commercial system then I would refer you to "Why Flow Rates are Critical in Aquaculture" written by Paul Van der Werf.

Fish are such a wide topic. My advice is grow what you like to eat, or grow what you like to look at, but don't grow what does not belong in your neck of the woods.
Tilapia in Maine is going to require heating the system, and take it from someone who has been there, it gets expensive. Catfish, are a good all around fish, but even though they can survive, they will stop growing during the cold days of winter. If you live in Florida or Hawaii you might like to grow tilapia, but even in Florida the winter will require some heat.
The nice thing about Tilapia is they grow pretty quick, they are hardy, and they reproduce well, but catfish kept in a warm water tank will also fulfill these qualities. If you live in a very warm climate, go for it. But most of us will be better off with a local fish that is acclimated to our area. Perch, Blue Gil and even trout are being raised in cool climates.

Larger systems are more stable, but start small. A 100 gallon tank with about 16 lbs of fish and 16 sq ft of garden is a very nice system. You can expand the grow bed on that system a little, and stock the fish a little heavier, but for starters it's best to keep a light fish load.

Breeding Fish - I have found that fish will breed without my intervention. But some like to identify the males and females and place one male among several females. Sexing fish is not easy, but Robb Nash has a good method in his link. Once the fry are available it is a good idea to separate them so they will not be eaten.

Compassionate Killing of Fish

Inhumane and totally unacceptable slaughter methods, that can take a long time for
fish to lose consciousness and die, should be prohibited urgently. These include
suffocating fish in air or on ice, bleeding to death without pre-stunning, and the use of
carbon dioxide for stunning.

Only slaughter methods that cause an instant death or render the fish instantly
insensible to pain until dead should be permitted. These include percussive stunning
techniques whereby fish are rendered instantly unconscious when carried out

I use a 1" dowel about 16" long to club my fish. The easiest way I've found is to hold the fish in the net so that they don't slide out of your grasp. Wait a moment until they settle down and make one swift blow to the top of the head. Death is instantaneous. There is no suffering, no blood, it's just a good clean kill.

Fish Food can be a major expense if you don't find a good source. I buy mine at Tractor Supply where I get 50lbs for $18.00. The important thing is to look for about 32% or better protein. For your fry you may wish to buy a more expensive product with higher protein. Some foods will leave a lot of detritus so you may want to experiment. How much and how often you feed your fish depends on temperature. They will not eat as much when cold. Under ideal conditions you might expect to feed your fish about 1.2% of their body weight. I like to watch them feed and if they leave food after a few minutes then I cut back just a little until they don't leave any food. Take note of how much your fish eat to be sure your feed rate is approximately 1.2% of what you guess they weigh. If not you may have a problem with water quality. 

Wicking beds have many advantages when growing fruiting plants. Unlike lettuce, and kale which are not particular; tomatoes, peppers, squash, melons, and especially root crops prefer to get their roots down into the media and better yet the complex soil web provided by real dirt. With wicking beds we get back to mother nature, and let her, and all the microorganisms do what they have done since the beginning of time.
Scarecrow's demonstration wicking bed

Aquaponic systems are prone to deficiencies.  Iron being the most deficient mineral of all.  By using wicking beds in an aquaponic system the best of both worlds is found.

Earthan Beds - Paul Van der Werf presented his design several years ago.  I believe it was May of 2011.  His design differed from previous designs when he used 2" drain rock below the soil so that the water would flow unimpeded through the bottom of each bed. The water level remains about 2" below the soil.   He uses large pipes and an air pump to move the water.  Up til then 1/2" to 3/4" media was always preferred due to the larger surface area.  Paul determined that all he has to do is increase the volume of the media beneath the grow beds to compensate for the loss of surface area.  Now that's a win/win idea!
The Earthan Beds use large smooth rock in order to facilitate flow, but the surfaces of the drain rock provide very little BSA. (probably in the order of about 18 ft2/ft3).  With the rule of 1 pound of fish per 25 ft2 of BSA we would need to increase the grow beds to quite a large area.  For example just 100 lbs of fish would require 1800 ft3 of BSA or about 11 cubic yards of drain rock.  That's a lot of drain rock, so a standard media bed with something like lava rock should also be added to increase the BSA.  But if you have the room to add additional Earthan Beds I would go that route, and grow as much as you can.

Paul Van der Werf said while describing his Earthan Beds, "There is no great need to “cycle” the system as the soil will contain all the nitrifying microbes you can handle and will leach into the gravel substrate where your water flows very quickly" A system might cycle quickly with the help of some good garden dirt. This leads me to believe the BSA is not entirely dependent upon the drain rock even though the water does not flow through the soil.

Wicking Pots is a similar system. It uses pots placed on a shallow shelf or shallow tray where aquaponic water flows similar to Deep Water Culture (DWC) bed. The plants sit no more than about 1" into the water and the water wicks up into the pots. I first employed this system for cuttings. This has the advantage of being able to move the pots around as needed, but this exposes a lot of water surface to light and air. This exposure can allow algae to grow and water to evaporate but in my grow room I have never experienced these problems.

Pots sit in water over fish tank.    Fish can nibble at the Water Cress growing freely on the shelf.

You may wish to incorporate both of these wicking styles as well as DWC rafts and media beds, but just to let you know I like wicking and Earthan beds above all else because very little water is lost through evaporation. They conserve water which is the goal of any conscientious gardener.

DWC Rafts allow you to move plants easily. DWC should used in tandem with Media beds or Earthan in order to guaranty sufficient nitrification. Large commercial system like DWC Rafts because it allows them to rotate crops and squeeze the most production out of their green houses.

Raft systems are often built with rigid foam insulation panels which float in tanks about 12" deep. I personally do not like this material or method, and much prefer to use 3/4" plywood which lays on top of the bed. Net pots are placed inside holes just as they would be in foam panels.
This bed is actually a Kratky Hydroponic bed, but it uses the boards as I've described for DWC Rafts.
The bottom of the net pot is allowed to touch the water's surface.  This provides moisture to the media in the net pot by way of capillary wicking action. It's important to avoid openings because light will grow algae and air will dry the roots. Place the boards tight to each other and keep every hole filled.  The advantage is moist air around the roots, and a cleaner more stable grow bed that does not use environmentally awkward materials. Evaporation is minimal due to the top being closed. The plywood will last for many years, and can be coated with fish safe epoxy for even longer life. Giorgio presented his GM Raft System - an integrated aquaponic design in January 2012 and others have improved the concept. They may have gotten the idea from Kratky, but as far as I know Giorgio was the first to integrate the concept with aquaponics.

NFT (Nutrient Film Technech)
uses tubes The roots grow in the nutrient rich flowing through the tubes.  This is generally a way of conserving space by going vertical. The downside is the water gains or looses a lot of temperature.

Vertical Towers allow easy access and greater density, but I see no way to incorporate this into a 'Level System.' Bright Agrotech is the leader in this field. Their Zip Grow Towers are well designed and provide a modular approach that facilitates easy harvesting and transplanting seedling starts. This system will transfer a lot of water temperature to the surrounding air.

Dr. Nate Storey pictured above has many very informative videos about gardening with aquaponics.

Bioponics is aquaponics without fish. There are many advantages.
1. There is no need to purchase fish food.
2. No detritus from food to clog up the system from humonia
3. Bioponics allows changes to the water chemistry without worry of killing fish.
4. You can use pesticides that would harm fish.
5. You can grow within a wider range of temperature.
6. There is no need for a fish tank.
7. Less to worry when you leave for a weekend.

The disadvantage is the system does not produce animal protein.

Generally humonia (aged urine) is used instead of fish. Aging the urine will kill any pathogens, but to be practical urine is not a likely source of pathogens in the first place. If humonia grosses you out then you might be interested in another method. I am testing to see if grass clippings and weeds can be substituted for humonia. My initial tests indicate that grass clipping will provide plenty of nitrogen. David Epstein at has been doing some interesting experiments using only plants to feed fish in aquaponics. I am hoping to find a way to do the same in Bioponics.  I have found that grass clippings and weeds can cause detritus.

Plants -My advice is to grow plants you like, and costs you the most to buy in the grocery store. The important thing is to grow with the season. The short days of winter will not support tomatoes. Green leafy vegetables do best in Winter. Cilantro might not grow too well in the summer if you live in a really hot climate. Choose what grows well in your area.

Green Houses or Garden Rooms as I like to call them are great, but beware they can get very hot in the Summer and cold in the Winter.  I use mine for early starts.  Keeping the frost off can be quite an expense.
I also built a grow room, separate from the green house.
I attempted to design my grow room by calculating BTU losses and gains, but after all the number crunching was done I finally understood that relating the math to my real world design had become too complicated for me.  I built a highly insulated grow room, and have found the temperature is be acceptable in the summer even though the outside temperatures were 105-111 F for several days.  All I did was open the windows. Inside the temperature reached high 90's but the fish loved it and the plants did not mind.
Winter on the other hand causes me grief when nighttime temperatures drop to 20F.  I ran a 1200W heater several hours a day and kept the water at 72F and the room stays at about 60F, but humidity and my electric bill have caused me stock my tank with catfish.  I don't want to do that again.  Mold became a huge problem.
Outside looking into my grow room.  Evaporative cooler was not necessary
The grow room is inside an uninsulated metal shop, and the walls and ceiling of the room are insulated with R19. The tanks are also insulated with R11. The problem with this grow room is humidity in the winter and not enough glazing. The room measures 10’x10’ with an 8' ceiling. The single pane glass faces south and measures 10 feet long by 40" tall. If I were to do it again I would add some glazing above the grow bed. East and West windows are probably not so important because the angle of the sun is so low.

To fasten fabric or plastic film you can use PVC as shown in [this video]

Geodesic Dome Calculator

Rocket Mass Stoves are used to heat garden houses. They are affordable compared to running a gas heater, but require a little more attention.

Evaporative Coolers are often used in green houses, they do a really good job if you live where the humidity is low, but running a fan to cool the green house is once again wasting energy. Our summers often hover near 100F or above. I've found that all I need to do is open the garden room up and let the air blow through. This also allows bees and other insects to pollinate your plants.

While on the topic of green houses and living with Mother Nature, I have a few more things to say about energy. Growing with lights is not economically feasible. Possibly, if you were to use LEDs, but how does anyone justify the initial cost of that type of system for vegetables. Grow with the seasons. Leafy greens in the winter, tomatoes and peppers in the summer, and forget the high tech crap.

Floors - I promise, you will spill large amounts of water. Any floor under or near an aquaponic system should be able to handle being wet. Wood does not fit that description.

Pipe sizes are important. Once a hole has been bored into a tank it is very difficult to change the size. 2" pipes are minimal. The flow of water is impeded by small pipes, and each turn also adds resistance. It's very important to build your system with adequately sized pipe the first time in order to avoid problems with water flow.
Gunk clogs pipes and makes them run slower over time.  This is one reason for large pipes and why bell siphons fail.

Insulation and building below grade can help maintain water temperatures. You will have to decide if your climate demands this extra effort. My experience shows that it does help but since there ia a lot of surface exposure it merely servers to soften the swings rather than hold a temperature. If you choose to disregard my previous advice and plan to heat the water then I would definitely go to the extra trouble of insulating.

Lights can be used to extend the grow season. I'm not advocating grow lights to grow plants to maturity, but only to add a couple extra hours in late winter to get your starts going early. If you should choose to do this, do not use any type of florescent or CFL lighting. They are far too expensive because they have a short 1/2 life, and the mercury is very toxic if a bulb should break into your system. My favorite is Ceramic Metal Halide. They have the best spectrum and the heat does not go to waste in the cold days of late winter, which puts them on par with expensive LED lights. Ceramic Metal Halide is being discontinued even though the replacement may not be as good. But I bought a few extra and will make them available if the supply runs out.

Heating is a waste of energy, but occasionally using a heater to get through a short cold spell might make sense. Building a heater from a water heater element is quite easy, but I would caution you to use an Incoloy type water heater element (120-1500-ELD. You can purchase them online here at

Heat pads are also a smart way to keep your seedling at the right temperature.  These small pads have a built it thermostat to keep a tray exactly at the right temperature.

Solar is an option I have not used. It might be a good solution for you.

Starting from Seeds is the least expensive way to grow. Buying plants from a nursery can expose your system to unwanted pathogens, disease, and bugs, but this is a rather small risk in my opinion. Commercial nurseries are very careful now days to use sterile media and deliver healthy plants. The advantage to buying your starts is grow bed space and labor. Starting from seed requires using part of you grow beds for plants that will take time to mature. Buying a plant from the nursery allows you to make better use of your space. But if you are like me you will prefer to buy seeds of particular heirloom plants and save the expense. I start my seeds directly in the bed where they will grow as well as in trays. Transplant shock is rarely an issue in aquaponics. I like to place a bit of Azomite and Insect Frase in the media when I plant a seed to give it a good immune systems, and all the nutrients it will need when it grows up.

Keep a Log. Especially for the first year or two you should keep a log of when you plant, and all of your water tests which should be done everyday until your system completely stable and you get to know it so well that you can immediately tell if something is off. Use your nose and eyes and ears. You may have a dead fish, or one of your pipes may be getting clogged. If you become acutely aware you can save yourself a lot of grief by detecting these things early. If you become a professional grower you will want to keep a detailed log to protect your livelihood.

Sea Salt cures a lot of fish problems, and is the least harmful treatment. More fish die from people trying to treat their fish. Salt is not good with catfish and can be hard on some plants like strawberry, so you may have to experiment.

Black Soldier Flies are an optional food, and many choose to build a small bin to raise them. I have not had a great deal of success raising them. It is something I would advise looking into for a very good source of free protein.

Midge Flys are a gift that may find their way into your system. The small red or tan worms hide in the media, and the bottom of the fish tanks and are very good food for your fish. The Midge Fly looks almost the same as a mosquito, but Midge Flys have no stringer. I guess that's what you would call the part mosquitoes stick you with. Anyhow they are easy to confuse, but midge and their larvae are excellent fish food and they cause you no harm.

For more information on live food download [this PDF].

Other foods such as duckweed, and Moringa tree leaves can be grown for both you, and your fish. It's good for your fish to have several sources, and since living plants will not decay you can be sure your fish will have something to eat if you are not feeding them enough. It is nearly impossible to grow enough duckweed in their tank. They will eat it faster than it grows so you will have to grow it elsewhere. I let water cress grow along the edge. It gives them something to nibble on.

Pest Control can be an especially difficult problem with aquaponics because you must avoid killing your fish. This is one the benefits of Wicking Beds and Earthan Beds. Pesticides are not likely to fall into the fish tank or radial filter. Fish tanks can be located away from the grow beds in a shed. Vertical towers are also far less susceptible.
I hope you will be very conscious of what types of pesticides you use. Many will kill bees which are becoming endangered due to bee-poisoning neonicotinoids. Rather than get into a pests control hear I will LINK you to a few posts I made awhile back.
The Yin and Yang of Pest Control
Fungal Diseases
Killing bees and birds

In the beginning I asked what your goals were. My goals may not be your goals and your resources will differ from mine, so our systems will differ. As I see it, Wicking Pots or Earthan Beds offer the best of both aquaponics and soil based gardening. Consistent moist soil, with benefits of a complete soil web and low water use. The integrated raised beds, fish production, and easy to care for gardens will be free of harmful chemicals. The use of airlifts reduces the power demands, and in the long run reduces your food costs. Bioponics is another interesting way to go.

I also plan to install some of  Nate's vertical towers.  He and his team at Bright Agrotech have done a lot of research, and share more good information about how to succeed with aquaponics than anyone else I know of.  Bright Agrotech's Co-Founder, Nate Storey holds a Ph.D from the University of Wyoming. Doctor of Philosophy (Ph.D.), Agronomy and Crop Science.  Nate knows what he's talking about. There is also a link to his Youtube channel below. Nate has documented outstanding results using his proprietary towers. 

Many are the considerations. You will probably ponder many sites and videos looking for ideas before you settle on one design, but I hope you will consider what I've said. If your system is not working the way you would like, take another look at this document, the [Rules of Thumb] on the Aquaponic Gardening Community site, and Kieth Tatjana's Optimization of Backyard Aquaponic Food Production System for answers.

Bob Campbell

Chico Gardens
Chico Aquaponics 

PS: Along the way I've found many good sites.  Here's a few I recommend in no particular order.
WaterRight Australia
ScareCrow's Garden
Rob Bob
Grow Your Greens
Wood Burning Stoves - Permies 

Some of the experts I like are
Vlad Jovanovic
Paul Van der Werf
Jon Parr
Nate Storey
Rob Nash 
Tetsuzan Benny Ron


Saturday, September 7, 2013

Earthan Beds

Over the past 21 months I have experimented with variations and combinations of Aquaponics, (vertical towers, wicking pots, deep water culture, and media beds), plus several other gardening methods such as Bio-Ponics, Wicking Beds, Hugelkultur, Two forms of Hydroponics (Dutch Bucket Hydroponics, and Kratky Method), and Dirt.

What I discovered worked best for me was all of the 'ponic' methods -Aquaponics, Hydroponics, and Bio-Ponics The Kratky Method (a form of Hydroponics) also worked well, but the Kratky Method is limited to quick crops of leafy greens.

Wicking beds or Wicked Beds as the Aussies like to say,  provide uniform moist soil,  even when I forget to water, and they conserve water due to the bottom up watering method.

The 'Ponics' which are not normally soil based, provide nutrient rich water on a regular basis.

I am now ready to combine the techniques that I found worked best for me.  I was working toward this conclusion when I saw this link to the Earthen Group.  The details of this solution were instantly clear to me.  Paul Van der Werf  appears to have worked out all the kinks, and has detailed the construction of his system in the link above.

Since I built my Wicking Beds as conventional raised beds, and used sand in the reservoir I will have to replace that sand with 1-1/2" drainage rock in order to facilitate the faster movement of water from the Bio-Ponic or Aquaponic system.  I'm leaning towards Bio-Ponics because I'm not into eating fish, and it comes with less overhead.  Either way the nutrients will flow below the soil in the Wicking Beds.

This should create a very large area for nitrification, and be very good for the fish if I choose that path.

I considered utilizing one bed for the soul purpose of vermicomposting  Eisenia Hortensis (European nightcrawler) or more likely Eisenia Foetida (the red wiggler, Californian red worm).  But the leachate from a worm bin would not be beneficial to an aquaponic or even a bio-ponic system.

Converse  wrote a very good description of the risks involved. [LINK]

To be clear-  keeping red wigglers in all of your grow beds is a good idea, but the leachate created in composting worm bins is better suited for a Bokashi Compost than used directly in the garden, or introduced to aquaculture, so even though it may sound like it would increase the micro-nutrients in the soil, it is not recommended.

Since I first made this post I have converted two of my wicking beds to Earthan Beds.  They are working very well.