I feel strongly that I have the Perfect System design for any climate.
CLICK HERE for the details of that post.
I will continue to update that article as I learn more so check it every once in a while.
But be sure to take advantage of the links below. These are the gems I've found.
- Breeding Fish
- Jon Parr (LINK) - I assume you have blues, Bob V? Blues will breed at 8 months,
mossambicus at 3 months. Water temp needs to be above 80, and a water
change always triggers a spawn. Feed them constantly, as often as you
can, a belt feeder is best. First time mothers often have small batches,
25-50. Seasoned girls have 300-500 eggs each time, and 500-1000 for
older bigger mothers. Ken, over 1000 eggs is pretty rare, but 2500?
Maybe if your mothers are 3 or 4 lbs, but not 8".
Bob V, size doesn't dictate sex, especially with young tilapia. In my experience, the first male to hit 2" becomes dominant, and all he can do is dance for the ladies. His focus is so intense, that ge will neglect eating, and invariably another male will pass him up sizewise and take over the lead role. Once a female starts breeding she doesn't grow much more, or grows very slowly. If you want bigger females, keep them from breeding by segregation or water temps below 75
- Vlad (LINK) - ...Things are way, way
too wet. Stems, leaves, crowns the works. Next time one of your
seedlings flops over, carefully excavate the hydroton or rockwool around
the area where the stem meets the roots (called the crown). You will in
all likelihood notice a 'thinned out' portion of stem there. Like the
outer layer of the stem has been 'eaten' away leaving only the stringy
inner vascular tissue. Don't bother looking at the roots, as that type
of rot can only be observed later when the plant is a bit more
developed. That type of thinning, wilting and flopping over of seedlings
is caused by Pythium, a big lover of overly moist conditions and one of
the most economically devastating oomycetes (pythium was long ago
mistakenly classified as a fungus, and some people/books still call it a
fungus for some weird reason) of soil-less growing (but in soil
I've not ever had much luck starting any plants off directly in a DWC set up, because of Pythium wilt. So I start the off in net pots and hydroton but NOT in a DWC bin trough. I give them a week and a half or two, then plop them in DWC. This has worked out much better for me.
Your rockwool cubes look totally soaked as well, and it's a very, very bad idea to have wet leaves close to any type of light, or even lights on while leaves are wet (though flouros that are too far away anyways, would probably be the least harmful scenario, still not good though)...
Ceramic Metal Halide Lights
- Jon Parr (LINK) - .CMH (Ceramic Metal Halide) are not necessarily the best, but they are my favorite. MH (Metal Halide) emit blue
light for veg, HPS (High Pressure Sodium) emit red light for flowering, and CMH emit full
white beautiful spectrum, including UV. Photosynthesis uses a fairly
narrow spectrum of the blue and the red, and non at all in the green, in
fact reflecting it, which is why plants are green. The jury is still
out on how exactly UV is used, but side by side comparisons show
healthier plants when a little UV is added, IDK. I do know that HPS are
cheaper, about $20 and on the shelf at Home D for a 400W, as opposed to
$50 for a CMH 400W. Bob, and Kevin, you will be amazed how cool HID
lights are compared to flouros. The bulb itself is hot, yes, but the
total heat generated per watt is less, and a vertical CMH bulb needs no
cooling at all, not even a fan, as the natural convection draws a
cooling air current upwards past the bulb. I pay $.45 per KWH, so
efficiency is paramount, meaning no reflectors or glass to suck lumens. I
hang a vertical bare bulb, and situate my plants around it in zip-grow
style towers. Ideally, I don't want a single photon striking anything
but plant. Is the UV dangerous from a CMH? Yes, probably, just as
dangerous as it is from the sun. I have never noticed any discomfort,
but I am in the sun working every day anyway. I've read that sensitive
people advise wearing sunglasses, long sleeves, or even sunscreen if
working around bare bulbs for extended periods of time. I have them
lighting up my whole shop, but they are in closed fixtures with a glass
panel, which blocks the UV.
I get my CMH here, and ballasts, and sockets are available for about $15 at your local head shop. http://advancedtechlighting.com/cdmed18.htm For flat grows like Bob and Kevin have, you'll want to add a wing style reflector to bounce light back down to the plants. The linked site also show some pictures of failed bulbs, and how the arc tube remains contained. The Phillips brand they sell are rated for open fixtures, a big plus for bare bulbers like myself.
- TCLynx (LINK) - Bottling
pee and waiting for the enzymes to turn the urea content into ammonia
can take a while. In the Liquid Gold research I did a while back I
found sources that said to bottle the urine until the pH got over 9.
This was usually the indication that the urea had converted to ammonia.
How long this takes can vary but 3 weeks seems pretty common.If you use the urine sooner, like perhaps you have it bottled for only 5 days or something, you may test and get an ammonia reading but that reading will only be telling you how much has converted (not how much may be left to convert) so if you were to dose your system with minimally aged pee, the ammonia levels could continue to rise after dosing and this could make figuring out your next needed dose difficult.
Test Kit Longevity
- Testing pH
Vlad Jovanovic - Eric that's a really good question. Just FYI though, in terms of the "false low" pH reading that you get right out of the tap...it's the CO2 trapped in the water that is the culprit and not Cl. (Eric, Cl has a pretty high pH of 11 point something, so it could never be that. It's good to off gas Cl for other reasons though).
Carbon dioxide is only water soluble when pressure is maintained (like in your water pipes). In this dissolved state it is called carbonic acid H2CO3. Since it is a weak acid, when you measure water right from the tap without letting it sit out for a day or so, it will give you a false low pH reading. Once the the carbonic acid has a chance to off-gas into CO2, and escape into the air, you can only then measure the pH and confidently obtain a realistic reading. The difference is pretty big too. One to one and a half pH points (or more) is no small matter. If anyone cares this is the relation...
CO2 + H2O --> H2CO3
After that the carbonic acid reacts slightly (and reversibly) in the water to form a hydronium cation H3O-+ and the bicarbonate ion HCO3-
H2CO3 + H2O --> HCO3- + H3O+
This is also why when you open a bottle of distilled water, first you can't zero in on a reading (distilled water having no ions and all, and therefore no determinable pH. But, then as the distilled water reacts with the CO2 in the air pH you can hone in on a somewhat stable reading and will always get an acidic one (barring any other contaminates). This caused me no end of grief for a few days a good while back in my college days...having always heard, and believed, that distilled water has a pH of 7...This is not true. the pH of distilled or demi water is "indeterminable"...Anyways.............
The chemistry probably only interest Eric, but anyone reading this (ever) needs to know that you have to let your sample water (tapwater, well water...anything that's been in a pipe or through pipeworks) sit out for a day or so before testing it's pH. If you don't, in a day or two you'll be scratching your head wondering what is causing your waters pH to "rise"...
Comment by RupertofOZ
How do I keep my ph down keep going up to 8.2 no matter what I do. I change all the water and clean all the clay balls
The problem relates to a high carbonate buffering capacity... in your source water...
Treating the tank volume with acid... apart from being potentially dangerous if you have fish in it... is like pushing marbles up hill with your nose...
Yep, you'll see the pH drop when you first add the acid.... as it initially consumes some of the carbonate buffer in the water...
But having done so...i.e the acid is neutralised by the remaining carbonate content.... the pH then just rises back to where it was... usually within a couple of hours...
Continuing to treat with acid... will see the same thing occurring....
UNTIL.... all the carbonate buffer is exhausted...
Which would occur.... IF you did NOT add any further water... i.e "top ups".... OR a water change....
Because your source water is high in carbonate buffering capacity.... changing water, especially changing "ALL" the water... is just negating any effect that adding the acid might have acheived...
i.e... lowering the carbonate buffer....(somewhat)..... but just adding more carbonate buffer back to the system.....
DON'T try and treat your tank volume.... treat your top up water... to the pH you want (even if requires several doses)....
Doing so.. means that you wont be adding carbonate buffer back to your system.... and with nitrification.. and treated top ups.... your system pH will fall over time...
DONT use lemons, vinegar, limes etc.... apart from the potential anti-bacterial properties... you'll need a truck load to have any effect... or at least any lating effect.... (lots of cost).... and meaningless if you don't treat your top up water....
Use Hydrochloric acid.... it is simply the cheapest, most effective... and recommended (for several reasons).. way to lower the pH....
Your high carbonate source water.. will actually be beneficial... eventually... when your pH has fallen to the point that it requires buffering upwards...
As all you'll need to do... is top up with some "untreated" carbonate buffered source water..
- Winter Garden
- Comment by Chris George
System Design Considerations
Many people use gallon of fish tank to gallon of grow bed ratios. This has a minor flaw, because nutrient uptake and removal by plants is directly related solar surface area, and only indirectly related to grow bed volume assuming root development plays a large role in your particular crop. But before you can say something like 3 sq. ft. of grow bed per gallon of fish tank, you need to think about stocking density and feed conversion ratio (FCR).
In this industry everyone is taught to sell their tilapia when they are no more than a year old. The reasoning is that when fish are small and young, the FCR is smaller, and less feed becomes more fish faster. That's useful thinking in the aquaculture world, but lacks a certain breadth of consideration in the AP world. You might consider an aquaculture strategy that focuses on growing larger, older fish. Remember that AP systems produce about $4 of produce for every $1 of fish in a Rakocy style system which has been optimized around fish production. By lengthening the grow-out period for your fish, the FCR will increase, but it will also stabilize allowing you to have better control over the nutrient stream to the much more important produce side. Additionally, higher FCR means more nutrients end up in the plants than in the fish... which is where the money is. This in turn should imply that larger fish lead to larger grow beds.
With that in mind, its probably a good idea to see your system as one that will go thru many changes when it is new. Then as your fish mature, and your nutrient stream stabilizes, you will be able to fine tune the grow bed surface area to match.
Gravel beds, a type of fluidized bed reactor, are the oldest and most established form of modern aquaponics, and were first used in the work of Woods Hole researcher John Todd at his New Alchemy Institute, and Dr. Mark McMurtry at NC State.
Dr. Jim Rakocy, a RAS (Recirculating Aquaculture Systems) aquaculture specialist at the University of the Virgin Islands in St. Croix, abandoned gravel beds because he wanted to work around the issue of sludge build-up. To avoid sludge issues, he developed raft culture, which in the absence of a bed reactor, required settling and degassing tanks. This system falls short of optimal for several reasons: 1) you're spending money on nutrients your plants need that you then remove from the system wasting resources 2) his floating rafts blocks most of the air-water interface for gas exchange intensifying the need to waste electrify on compensatory aeration, and 3) this system design is fish-centric, obsessed with how many fish you can cram into a barrel, when Jim's own publications showed that the aquaculture side was a minor contributor to revenues, and 4) only a very limited number of plants can tolerate having their roots immersed in water 24/7. Typically plants with low nutrient requirements and low ability to scrub nutrients from the water.
Tom Speraneo, is credited with the first use of tilapia in AP systems, but also is credited with cycling the water level in the gravel beds, creating enormous amounts of temporary thin water surfaces for gas exchange, and facilitating aerobic RAS waste processing. But the other interesting development was that it made the beds capable of sustaining active vermiculture, which further breaks down and decomposes the solid wastes, and restores lost nutrients instead of wastefully removing them. This seems to have been confirmed by the systems popularized in Australia by Joel Malcolm and Murray Hullam, with Murray claiming to have systems that have run without any waste removal being necessary for over 3 years. Similar results have occurred in Hawaii with Glenn Martinez's system.
Using the archaic meaning of vermiculated of "worm eaten", we can call these vermiculated fluidized bed reactors, and their use should free up a great deal more nutrient from the same amount of feed input, allowing you to focus on the much more profitable produce production side of an AP system.
With that in mind, Wilson Lennard has shown that raft cultures seem to be slightly more productive with low nutrient crops like lettuce, whereas most crops cannot be grown in rafts at all. Since lettuce has a very fast seed to crop cycle, it can provide stead cash flow while waiting for more valuable crops to mature in the gravel beds, and with all the extra nutrients available, there's plenty of reason to have both in your system design. This will also increase the total system volume, which is good for fish, and if you design your deep water wells with tops that are not floating on the water, you'll have greatly enhanced gas exchange surfaces.
It would probably be a good idea to avoid NFT (Nutrient Film Technique) completely if your system includes fish production, because a thin layer of water spread out over long distances is basically a heat exchanger, which will cause diurnal temperature swings in your fish tank greatly adding to their stress levels.
Vlad Jovanovic yesterday I've seeded and grown out thousands and thousand of plants in two inch net pots filled only with hydroton. My germination rate is quite high using hydroton only. There might be some old pics on my page here...or somewhere. But basically, like Devoid, I built a 4x8 table (lined it with Duraskrim) and plumbed it to a trough). A pump on a timer floods the table with an inch and a half or so of water.... as often as is necessary according to what season it is (temps/humidity). There is a short standpipe (that keeps the water level at about 1.5 inches)...when the pump stops, the water drains back into a DWC trough via two small holes near the bottom of the standpipe... From here, these rafts get transferred into a nursery trough that has about 8" of water. From there the net pots get taken out of this tight spacing and transferred into production rafts (regular 'ol 2' by 4' rafts with 8" on centers hole spacing)...
- Hi guys...the chart that Jim posted actually applies to soil gardening and not hydroponics (or any other type of soilless culture). It is common to mistake the charts as the two are often floated around "internet-land" rather indiscriminately :)
Most (decent) soils have a vastly different cation exchange capacity than most common soilless mediums...or "worse" yet, water culture (as in a DWC scenario, this is why, in part, in a low nutrient density environment, or one where pH is rather high, plants in the DWC portion of a system tend to exhibit visual signs of deficiency before their counterparts that are in a media filled grow bed...even though they are in the same system)...here below are two charts (soil vs soilless) for comparisons sake...
Notice that the soil chart is much more forgiving...
Oh, and no...there is nothing "magical" about AP. How plants grow without soil, is how plants grow without soil. That said, a well seasoned, mature, micro-biologically thriving AP system seems to display more of that "soil like" forgiveness, that a new or micro-biologically sparse one (much of this seemingly has to due with niche nutrient cycles beyond ammonia oxidation) .