Having seen how well my Aquaponics system can do, I am ready to add a third bed to the system I have up and running, with the short term goal of adding another 2 tote, 3 bed set up behind the garage. Personally, I like my grow beds to measure approximately 10″ deep by 32″ wide and 7’6″ long. (yours can be whatever size you want them to be, obviously). The factors weighing in on these particular dimensions had to do with (a) the stack of 2″x10″ boards ranging in length from 8′ to 15′ long. (I pilfered these after they homes across the street were built and this pile -and I mean PILE of boards was bound for disposal (probably 20-25 planks), (b) the width I could easily reach across from one side, and (c) the length loosely based on a standard platform (which is (2) IBC totes side by side). Accounting for a slight overhang on each end, the ideal length came out to between 7’6 and 8′ long. The width also works out well, leaving enough of a gap to reach in and work on the inside of the tanks as needed for cleaning, etc.
Using the 2″x10″s as walls and some 3/4″ plywood I found on the rafters in the garage as a base, and a box of nails and some wood glue I had left over from a previous project, I had the basis for a box. A trip to the hardware section to purchase some angle braces, and some pond liner gifted by a newghbor and I was good to go. If you’re lucky, you might have something large enough to use as a liner for your grow bed, just make sure that it is ‘food grade’ material.
Having worked in the construction industry for oh-so-many years, I had some 3/4″ pvc pipe laying around. Since the building of the hoop house, I had some extra 90s, but still needed a trip to a couple of different stores to procure various fittings, pumps and hoses. The most expensive of theses, by far, were the water pumps and air pumps, along with the air stones for the system. I think the water pump was $50 and the air pump and the airstones combined was about $60 per IBC tote. So, 2 totes, 2 air pumps and stones, or $120 for the pair. I have found that 1 pump can handle the 2 grow beds, but we will have to check as I add a 3rd, and perhaps, even a fourth grow bed to the system.
Some of the research that I have done over the years, and corroborated by several different sources, says you can have between 1/3 and 1 pound of fish per square foot of grow bed space. With my 2 – 275 gallon IBC totes as fish tanks, combined together with piping, thats 550 gallons of fish tank water in which to grow the fish out. That’s not to say I’m going to grow that many, far from it. Besides, my grow beds are barely 20 Sq’ feet each, meaning the most I can have right now, is about 50 lbs fish, with all 3 grow beds planted out. (The other way to look at this is a MINIMUM of 27 lbs of fish 2 a 1:3 ratio)
Is it possible to be inhumane to a fish? Hmm, I will skip that philosophical question by simply stating I wouldn’t want to ‘crowd’ my fish, nor do I have any plans to do so. But back to the grow bed. Using the dimension above, 8″D x 32″W x 7’6″L, that is the equivalent of about 20 sq ft (2.5 x 7.5 = 18.75 ft sq). If I eventually had 200 pounds of fish, maxed out, that would mean TEN grow beds to take up all those Nitrates. Or, I can simply limit the fish to 50-75 pounds, and between 4 and 6 grow beds per 2 tote system, which is my ultimate plan.
When the temperatures rise, the fathead minnows will begin to spawn, as will the catfish, but the minnows will never get any bigger than a minnow. Eventually, this tank will need to be pared down, and as for the catfish, well, they will make for a nice fish fry at the end of summer, potentially, and the fathead minnows will do nicely to ‘fatten’ up the cats before dinner.
But thats for another post, and yes, there WILL be pictures!