Tuesday, December 27, 2011

Gravel Bio Filter

Here is a concept drawing of a bio filter which filters from the bottom up
I have used this is the type of filter for many years without problems.
A spray nozzle is angled on the bottom of the power wash tube which is connected to a garden hose to stir up the waste.
The 2" inlet also serves as a waste drain.
A tee with either a diverter valve or two separate valves allows switching from normal operating to backwash mode.


This page continues to get a lot of Google hits, so I have added this drawing to demonstrate how the bio-filter in my pond was built.

The gravel media is suspended above an open space.  I did this by building a cement block cistern on top of a 6" concrete slab.  The blocks were laid dry and then filled with concrete.  Inside I laid 1-1/2"x8"x16" paver bricks on edge to create a shelf for the PVC tubes to rest on.

The PVC tubes are 1" pipe and contain a piece of 5/8" rebar to give them the strength to support the gravel.  The ends are capped to prevent the rebar from rusting. Yes it takes a lot of these pipes laid side by side. Over the top of these PVC tubes I placed a piece of PVC fencing material to further support the gravel.

There is a drain and an inlet pipe placed at the bottom.  Both are mortared in place as is the outlet near the top.  Then to prevent leaks I coated the entire inside surface with Thoroseal .

I have also built small filters inside of plastic olive barrels as depicted in the drawing at the top of this page.  The gravel is supported by a PVC cage.  I'll let you use your imagination rather than attempt to draw that.


 Another idea I have is to plumb the spill tube down to the bottom and bring the inlet to the top.  Dirty water is filtered down through the gravel.  A mesh on top of the gravel would facilitate cleaning

This would facilitate cleaning.  A mesh could be laid on top of the gravel and periodically rinsed off

SketchUp Link

An under ground aquaponic concept

With weather going from 115F in the Summer to 20F in the Winter I have been concerned about insulation and maintaining a consistent temperature.  By insulating and placing a large portion of the tanks under ground I may be able to control the water temperature.

Below is a concept drawing of what that might look like.   There would be a covered opening over the sump tank which would also provide access to plumbing.

  • The sump tank contains the pump which will operate 100% of the time without a timer.
  • Water from the sump tank is poured into the fish tanks.
  • Then into the settling tank using a bottom pickup tube not shown here
  • As water is pumped into the fish tanks it seeks the level of the spill tube which runs to the grow bed.
  • The water percolates through the grow media filling the grow bed
  • When the water reaches the height of the siphon it is dumped into the sump tank as clean water.  

An idea I have for a buried system

Some of the features I like in this design are:
  1. Reduced exposure to UV will help prevent damage to the polyethylene IBC's
  2. One pump design with no chance of pumping the fish tanks dry
  3. Well insulated
  4. Looks very clean with most of the mechanical system hidden underground
  5. Easy to add additional grow beds
Shown from the back side

Some features I don't like are:
  1. Plumbing is more difficult to access
  2. Grow beds are low to the ground
  3. Periodic cleaning of the bio filter may require significant effort
  4. The initial cost of digging the hole
  5. Possible problems from ground water (our water table can raise in the rainy season.)
SketchUp Link to this drawing

Monday, December 26, 2011

IBC's home!

I had quite a long way to travel with these IBC's, but with careful planning, and rope they made the trip without incident. 
As you can see this looks a little precarious.

A trick I would like to pass on is to tie the top of one to the bottom of the other at every corner, 
Then tie them to the sides of the bed, with square knots once or twice to each side to ensure that the load will not shift.
That rope over the top is doing nothing.

This is also a handy trick that will allow you to stack and drop the top container all by yourself.
As shown below it's a simple matter of just tilting it down to the ground.

Friday, December 23, 2011


I have located a source for 3 IBC's on Craigslist at $60.00 each. Adding about $80 for fuel it's still a good deal

These Spill Containers look ideal for grow beds!  Linked in Info Tab above

Saturday, December 17, 2011

The Beautiful Future of Food

I'm excited to start this project.
This is my first post to establish a place where I can keep my friends updated.

First off I'd like to say I support Open Source and hope to fill these pages with useful information that will benefit others.

Here are a couple pictures of where I am right now.
My 1300 gallon Koi pond is a working aquaponic system that has been established since 2004.  I grow ornamental plants in it.
My wife and grand daughter at the side of the pond

Lush healthy plants keeping the water clean

The pond uses a 3'x3'x7' gravel bio filter and a 3600 GPH pump

This sketch is my vision of the aquaponic system where I will grow food.
I've been researching and learning from those who have gone before me.
This is what I have come up with.
My current plan for a Vermiculture Aquaponic system
SketchUp Link to this drawing

I plan to use one pump and a bell siphon in each growing bed to support a Vermiculite Aquaponic system.
The 12" deep beds will be 15 feet long and 24" wide for a total of 60 sq feet of growing area. It will be  elevated above the sump tank at a comfortable gardening height of about 30".

This is a simple low tech approach of reproducing the natural cycles of life with optimum conditions.  It uses no timers or solenoid valves - only one pump.

The fish tank is slightly higher than the grow beds.  The over flow spills into the growing beds and fills until the bell siphon dumps the solution into the sump tank and is then returned to the fish tank.  As a safety mechanism, I plan to also install a stand pipe above the maximum level of the bell siphon in order to insure that the water will never over flow any of the tanks.  A venturi placed on the plumbing from the pump to the fish tank will help add additional aeration to the water.

Eventually I would like to grow in a controlled environment with grow lights and climate control, but for now I plan to build this outside.  My experience with hydroponics in a green house is that the hydroponic system proved successful, but too much attention and energy was required to maintain a controlled climate in the greenhouse . My dream would be to bring it all into an artificially controlled atmosphere for year around production. Take a look at he 321 video below to see what can be done.