Well, it finally happened. After a long winter of research, construction, and hard work, my aquaponics system, albeit small, has come to life. The fish have made it through the first few weeks in the tank and have given âbirthâ to a pair of tomato seedlings. The fish tank is an old 100 gallon Rubbermaid stock tank now buried up to the rim in the greenhouse. The tank is not only a home for the fish & the food source for the hydroponic system, but also provides thermal storage and humidification for the greenhouse. Thermal storage is important in my neck of the woods with the long, cold winters so ârecycledâ foam padding was added to insulate the outside of the tank before the unit was lowered into the ground. The hydroponic portion of the system is modeled after a small, PVC unit which I read about on-line: http://www.hydroponicsonline.com/11plan01.htm The construction of the system was fairly straight forward and the PVC hydroponics fixture went together in a few hours. The PVC frame sits over the tank with plenty of room for another system or two if I decide to expand in the future. The stacked setup allows easy access to the tank and the grow beds while making best use of the limited space in the 12x8 greenhouse. BTWâ¦the pump cost me $5 from Harbor Freight and runs on less average energy than my night lightâ¦er, if I used a night light that isâ¦not like Iâm afraid of the dark or anything. Unfortunately the pump runs on AC so Iâm working on an inverter so the system can be run off of a small solar panel that is already installed for the greenhouse. Iâm also building an electronic timer as the mechanical timers run for a minimum of 15 minutes which is unnecessary considering the cups fill in less than 2 minutes. Feeding costs are basically zero as the fish receive a daily ration of worms from a vermiculture system I stated this spring. Balancing the system was a real brain teaserâ¦a veritable real catch 22â¦the fish will die if there arenât any plants to remove the toxins from the water and the plants wonât grow if there arenât any nutrients from the fish waste. I opted to start slow with 8, ~3-5â brown bullhead in the tank and seeds in the hydroponic fixture. I figured the tank was big enough to support the small number of fish without building up too much waste until the bacteria in the gravel beds and the plants become established. It seems to be working but there are still plenty of opportunities for something to go wrong. Any old who, Iâll take this as a small victoryâ¦for the fish & plants anyway. The cat is put out as she was banished from the greenhouse shortly after her first fishing expedition and the âgarden weaselâ, aka Stitch the ferret, visits only during supervised work detail when he is allowed to cultivate empty soil beds. What I can I sayâ¦itâs a work in progress.