Olomana Gardens take on Aquaponics:
We practice Vermi-Aero-Aqua-Ponics.
Sure, we have the fish and the plants. We do the "total recovery"....keep the fish solids in the system, not flushing them out. We run parallel feed of fish solid water (from fish tank) to the bio-filter beds. Such that if I have three bio-filter beds, all three get an even distribution of the "dirty water". Then we have Indian Blue worms to eat the fish solids. We move the water input each week to avoid build up. Major ingredient, false bottom bio-filter beds. Either double tray (top one has lots of 1/4 inch holes that drain to a lower tray that has ONE drain, two inch that feeds to a common drain pipe (3 inch preferred) that goes to the siphon device. All siphon devices are remote...i.e. OUTSIDE the bio-filter bed. Thus when we drain our bio-filter bed, there is NO stagnate water in the bio-filter (as what happens when a bell siphon leaves and inch of water due to the air break). For a bio-filter we use Big Island black cinder. Calculated to be equivalent to 400 plus square feet per cubic foot of material. Bad news, it destroys the common mechanical water pump! The rock is soft and gets ground up to sand, that trashes most pumps. So we use AIR to pump the fish water from the fish tank to the bio-filter beds . I use a 25 lpm or 40 lpm air pump, silent, that pumps 120 to 300 gallons per hour )depending on line size and height. This moves the fish solids to the bio-filter, where the worms eat it. The vermicast dissolves in the water better than fish solids. But I will only get the nutrients that are in the fish solids.....so we hang a bag of vermicast in the BUCKET siphon. That is the remote siphon that is outside the bio-filter, and fills and drains at the same time and rate of the bio-filter. Now the vermicasting is from our garbage container/vemi-composter....so that I am adding nutrients to the aquaponics system ......getting all my micro and macro nutrients from the vermi-castings. It is so effective that the only thing I am really looking for from the fish is the nitrogen. All else is from the vermicast. Note that most "air lifts" are limited to pumping only 50% of the depth of water. Thus a 20 inch deep fish tank can only be air lifted 10 inches and if the water gets low....nothing gets pumped!. Our pumps use a one way valve that lets me pump a 20 inch deep fish tank to a height of 48 inches at a rate of 300 gallons an hour, using only a 38 watt Hakko air pump (40lpm). Max height is 10 foot, but you get less water per hour. A 25 lpm pump gives me 100 to 150 gallons per hour. Plus our air pump can pump a container, like a 55 gallon drum, completely dry.....I am not aware of any air pump anywhere that pump to zero inches of water!.
Next is the deep trough beds (not "bought" beds...type). We use deep trough for all the common reasons.....but NO FOAM floats. We use AERO beds, i.e. 1/4 or 3/8 inch or 1/2 inch plywood that is stained with an organic approved water based stain. The plywood is mounted two inches above the water...never in the water...and was the siphon flushes the water in the deep trough bed rises and falls and inch to so. We use only three inch pots and have the minimum water level set to 1/4 submersion in the water at the lowest water lever and rises an inch or so and the siphon flushes. The air layer avoids smothering the water like the foam float does....and no need for air to be pumped in the deep trough beds....per Dr. Rakocy's recommendation with foam beds. Plus....Much less solids build up in the deep trough beds.
Then when we do the drain/over flow on the deep trough beds, we use a "clear water pickup" that avoids floating trash. The water is flushed to the sump tank and aerated with slit tubes....with our "snorkel pipe, that flushes the water (safety against the slits being clogged) into the sump tank.
On our fish tanks we drain the water via ports 1/2 way on the side of the fish tank, with stand pipes at the 80 percent tank depth height, with clear water pickups, so that fish solids are picked up from the bottom of the fish tank and floating fish food stays in the fish tank. The 1/2 height port is such that I will "always have half a tank of fish water".
The use of the air pumps to remove the fish solids from the fish tank, uses 1/4 or less the electricity, and gives the cleanest fish tank water I have ever seen, and no one has clogged or worn out one or our air pumps yet. They pump sand, solids like 4 inch leaves etc with no problem.
Our Air pumps/water pumps lend themselves to solar installations, typically only 100 watt is needed.
We see aquaponics as the solution in cities and island where land is scarce, where water is scarce etc. The biggest problem is cutting the capital cost for installing the systems. Our systems in America run $2,500 to $5,000 installed, and that works out to around $90 per square foot. We need to get it to under $10 per square foot, to help feed the poor. In America this is a hobby....but more and more folks are going commercial and we need to see some success stories! I do not believe Australia or America has many success stories ($$$$).
We are installing one system a week in a school, college, home or commercial operation. We teach a practical "hands on course most Saturdays for only $100 per person ($50 for spouse). My favorite client is a orphanage or school that needs to feed hundreds of students who are going to grow their own food....no marketing....grow what they want.....educational.....and free labor! The garbage from the campus feeds my worms and thus plenty of vermicast available.....We could just do VERMI-PONICs... and forget the fish!
We give tours daily, allow pictures and track DYI. We host one or two schools a week for $5 to $25 per student, depending on age and intensity of the lessons. We have interns staying at our farm (we have six private cabins, $500 a month and they work 4 hours a day with us and then go surfing....we have interns 3 to six months from over 27 countries.
I live vicariously though my students....they are going all over the world spreading the word on aquaponics.