The blog ends rather abruptly, so I wrap up the cliffhanger here.
I acquired a large wellwater tank and removed the top with a circular saw. I cut a hole and added a Lexan window bolted in with stainless steel bolts and silicone sealant as a gasket. This left a fishtank of about 600 gallons. I placed it in the garage and filled it 75% full. This was stocked with Tilapia from the nursery tank. I added the sponge filters from the nursery tank and a 12" aerator stone.
Since I couldn't get the Tilapia to survive outside, I left them in the garage. To get the nutrients to the plants I used "offline aquaponics".
I added a rubbermaid garbage can beside the tank as a nutrient collector. A gravity siphon pulled water from the bottom of the tank into the collector. The siphon drained into a 5 gallon bucket raised above the middle of the can. The bucket was filled with hydroponic lava rock. A pump in the bottom of the collector returned the cleaned water back to the main tank.
Clarifying, the water flow was bottom of the tank through the gravity siphon into the bottom of the lava rock bucket through the lava rock matrix into the trash can and pumped back to the tank. To move the nutrients to the growbeds, I hauled the (nasty) bucket of concentrated fish-poo to the growbeds and poured it in. Then I reassembled the filter as described.
A layer of bleh accumulated at the bottom of the trash can, but I didn't have any issues with O2 concentration or nitrates. I did grow some lettuce in rafts on top of the tank, but I had issues with the fish eating the roots and pulling the rockwool cubes into the tank. I also did NFT on top of the tank, and it worked pretty well despite the poor lighting in the garage.
I harvested the plants and ate them, then disassembled the grow beds. The weight of the beds was causing my deck to sink. Oops. I grew out the fish and ate a bunch. They were good. Midwinter my heater failed and I had a large fish kill due to cold temperatures. Those got composted. The survivors got eaten in the spring. I drained the tank and it's empty in my shed now, awaiting another project. I did not record yield numbers of either flora or fish.
Here are my youtube videos about the fish. All but the last were recorded in my living room.
Tilapia Nesting Behavior
Tilapia Mouth Brooding
In the nursery tank
One Month Old
Last day in the nursery