Just started with an aquaponic system as a trial - 40 gallon media bed with perlite (tried perlite and coir but 1 floats and the other sinks so it didn't work well), a 40 gallon fish tank with some of the wife's goldfish in it (borrowed some from her pond), and a 25 gallon sump. Took a while to find the right combination of pump GPH and pipe size to get the siphon to work but now it cycles about once every 20 minutes (although it dribbles a lot at the end and never completely stops); the pump runs all the time. Growing peas, pumpkins (granddaughter's idea), spinach, collards, and lettuce. Using a 4 light T-5 grow light. Plants growing much faster than they do in dirt. Chemicals are doing well as I started with water from the pond. I want to switch to tilapia but need a plan. Need to know how many can go into a 40 gallon tank to start with and when do they need to move to larger tanks. The initial setup is inside but I built a new chicken pen and am converting the old pen and the area next to it into a green house (only place I had with water and power; chickens don't need power so they had to move) so I can move it outside when the fish need it. I was planning on using either 300 gallon rubbermaid tubs or galvanized horse troughs for the fish tanks and sump with 3'X5' media beds and a raft. Love the community/forum here. Have read a lot. End goal is just food for us and family and a hobby that doesn't just consume resources.