Last year I started an aquaponics operation with a greenhouse, a 300 gallon tank for fish, and two 3×12 foot grow beds full of 3/4 inch pea gravel in which I grew my plants. The tank was full of 100 Tilapia which I bought as little bitty fry and they grew up to be big fat 2 pound fish. The water from the tank was pumped into the grow beds where the gravel filtered out all the fish poop and the water was then dumped back into the fish tank. The whole process was set up with timers so it all happened automatically. The plants grew like crazy with all the fish poop, plus grow lights, and the water was heated up to 65 degrees for the fish, and it helped the plants to grow fast as well. It was a ton of fun learning about the process, building it, and then eating the vegetables and fish. I pulled the plug on the system and harvested all the fish about 10 months ago because I was getting ready to leave on my 2 month bicycle trip to Florida and I didn’t want to leave our daughter Sherri with the responsibility of taking care of it, there was always something that was going wrong and needing fixed. The whole system has sat idle since then, but I am going to get it started up again in the next couple of months, but this time I am going to raise channel cat fish instead of tilapia. The tilapia can’t survive in water under 60 degrees and it was to expensive to keep the water heated up to that temperature. Channel cat fish can handle just about any temperature of water. I will heat the water up a little bit with a solar system in the summer and I will pump the water through some coils, in my wood stove in the winter so the fish will grow faster as well as the plants. Wow, I love a project like this.