Once I decided to make go of it, I then had to get educated. I ordered a bunch of books and videos. I read all kinds of things on the Internet, including great information from the various Aquaponics forums (Yahoo Barrelponics group, Aquaponicshq, Aquaponics.net.au, backyardaquaponics, S&S Aquaponics and more).

Some of the better information came from Dr. James E Rakocy with the University of the Virgin Islands (UVI). While the rest of us have been having fun trying different things out, they have scientifically measured the effects of different ratios, plants, and fish.

The core info I found here.
http://srac.tamu.edu/getfile.cfm?pubid=102

This link contains a number of other good articles on recirculating aquaculture.
http://srac.tamu.edu/index.cfm?catid=24

This link has everything especially for those in the United States (fish, prawns, ponds, systems, etc).
http://srac.tamu.edu/

Initially I found that general guideline at MAXIMUM density of Tilapia was:
½ lb of Fish per Gallon of Tank
2 Gallons of grow bed per Gallon of Tank
or in metric
250 grams of fish per 4 litres of Fish tank
and 8 litres of bed per 4 litres of fish tank

But if you read further, what you actually find is that the size of the grow beds/raft system at maximum density is tied to the amount of feed fed daily. If your feeding a fish that grows slower such as trout (9 month grow out with 1.1:1 feed conversion), then you have less feed input each day, so you need less grow beds. Conversely if your feeding Tilapia at 1.7:1 and they grow out in 6 months, you need many more grow beds, or you must stock a lower density. A 4 x 8 foot grow bed will remove 0.4lbs (+/- .2lbs) of feed per day (according to the UVI research). Using the UVI data, I found that a 250 gallon fish tank raising trout required 1.37 beds 4 x 8 feet (1.4 to 1 ratio), while the same system growing Tilapia requires 3 beds 4 x 8 (3 to 1 ratio). Thats a big swing. In the end, the 2 to 1 ratio is a good average, especially if fish densities are kept below the maximum, or fish are started with fingerlings and the plant load grows as the fish grow.

So, I calculated the area of my greenhouse I was willing to dedicate to my initial aquaponics trial, and a 250-300 gallon (1000-1200 litre) fish tank with a 2:1 ratio to beds (1/2 gravel 1/2 floating raft) would work.

Then I pondered which fish to grow. Rainbow Trout are easy to get in Utah and easy to obtain permits to raise. Initially, they were my choice, but they like 55-60 degree water (13-16C). Not a problem in the winter, but the rest of the year, the water would need chilled significantly. I looked around for chillers and new commercial 1hp chiller runs $1,000-1,200 USD AND consumes 18amps at startup. Ouch, now it was getting expensive, I would need a new dedicated electrical circuit AND have to pay the power bill. Furthermore, very few plants do well at this temperature. So I abandon this plan and migrated to a warmer water fish.

My choices were narrowed down to the following:
1st Choice Silver Perch (easy to raise, tolerate a wide range of conditions and grow fast, not prohibited in Utah, but no U.S. Suppliers that I can find)
2nd Choice Tilapia (similar, and easy to find in the U.S., however, not permitted in Utah)
3rd Choice Hybrid Stripped Bass (not as easy to raise, not as much info, but legal in Utah and readily obtainable in the U.S.)

I also tried to get an Australian supplier licensed to export Silver Perch to Utah. I found that that was not going to happen easily. Then I decided to try and work through the regulations to get an exception to raise Tilapia in Utah.

Also, I hoped to raise a few Red Claw Crayfish in the sump tank or other tanks for variety.

Next I looked at various system options, commercial kits, DIY systems, Barrelponics, Nelson and Pade, Aquaponics Made Easy, etc. I found that in the U.S. a packaged system was very expensive, with fish tanks costing $1 to $2 per gallon of tank. I found lots of recommendations to use 55 gallon plastic barrels, IBC Totes, Stock Tanks and More. Next time Ill review my search for tanks and beds and what I ended up with.

Prev Post | Next Post