The book I am using is called Aquaponics, and instead of nutrient the ideal food is fish waste from either goldfish or food fish. However I had to pull the fish from the 1000 gallon pond that I raise my water lilies in due to a disease *(not using medicine and growing food on same pond) so for right now instead of hydroton I have my plants potted in organic potting soil via Living Earth.
I just added the tomatoes yesterday. Hydroton has zero nutrients and it would cost me about $450 for enough for my setup. I spent $10 on the potting soil. I will be picking up some 4 inch catfish for the pond in the next week or 2, have to drive a ways to get them, but I want a food fish in there.
I have tilapia in my setup in the greenhouse, but no food plants on it yet, haven't had time to work out the plumbing issues. The tilapia started in the outdoor pond but a temp below 45 degrees becomes fatal fairly quickly, I have 45 in the greenhouse (having lost the big ones to a late season cold snap IN the greenhouse), and a few in the house.
Greenhouse: raising aquatic iris and pickerel rush for my pond business. The fish at that time was a customer's injured koi, Feb 2014
tilapia Nov 27 2013, in the house
Before adding vegetables. I actually got the dirt idea when my blueberries died of drought and I tossed them in pots and set them on the big wide tray... they came back to life, noticed yesterday, bought some tomato plants. $450 for hydroton is a LOT of money. built the tray from curb wood - old garage shelves out of 5/8 plywood with 2x4 frames and braces. Scrap pond liner 11 x 12 taken off a customer's pond when we put in a hardshell. Cinderblocks ran about $20
Will post veggie photos when I get the trays filled up, maybe this weekend. Ideal time to plant in Texas is April, and I worked every day.