System 2, Outdoors in north texas.
The apartment design is the simplest of designs. A pump in the fish tank pumping to the grow beds which drained back into the fish tank.
The major draw back to this design is that if your plumbing fails, your fish tank can go empty.
A minor draw back to this design is that the water fluctuates in the fish tank. Some people say that this is unhealthy or stresses the fish but I have seen no practical evidence to support that claim [as long as the fish tank never gets too low or goes empty.] I often use my sumps as a nursery tank for sick or weakend fish and for fry grow out. I have noticed no significant effects of the water level changes in growth, health or behavior.
It is not really a design flaw, but the grow trays are only 6 inches deep and i wanted deeper grow beds to support taller plants. Six inch grow trays worked find for greens and herbs but tall plants like peppers and tomatoes want to fall over because there's not enough base support.
This second design is at a rental house and I am working with a space that i cannot modify so the space affected the system design considerably.
To protect against plumbing failure, the main difference in design is the addition of the sump tank. This is a modified CHOP (constant height one pump) design or some refer to as a CHIFT/PIST (constant hieght in fish tank/pump in sump).
To move my system/fish without deaths, I bought a new 300 gallon fish tank which I filled with water at the new property. I treated the ~300 gallons tap water water with 3000mg of aesorbic acid(vitamin C) to destroy the chloramines and let it sit with an aerator overnight. I was then able to move the tilapia in 5 gallon buckets to the new tank. Then over the next couple of days I moved the rest of the system
The fish tank stays constant height and overflows into the sump. The pump is in the sump and pumps to all of the grow beds which drain back into the fish tank.
I am looking ahead to north texas winters and I realize that I will not be able to keep the tilapia through a second winter(first was in the apt). So in anticipation. A few weeks after i got moved, I took a trip to buffalo tx to get 36 channel cats and 24 bluegill fingerlings. I have plenty of filtration for this fish load right now, but as the fish grow I am going to need more filtration so i get started building some larger 4'x8'x9,5" grow beds using wood and pond liner.
An architectural abomination, i am embarassed to post this.
Each new grow bed is built for ~100$ which is probably one third of what i paid for the hydroponic grow trays I used before The wood beds covers about the same square footage but due to increase depth provide more filtration (cubic feet).
Each new grow bed is about 150gallons or .75 CY. I priced hydroton for this volume and it came out to roughly 1400$. I decided to buy 1.5 Cy of expanded shale which cost a hair over $100. No brainer, right? I've already talked about pluses and minuses of expanded shale in a previous update. I should also note that smaller diameter also means more surface area for bacteria, which is another minor positive. I chose expanded shale over pea gravel and river rock primarily because it is lighter.
I moved to this house in march, The growth was decimated by insect and caterpillars in april and into may. Then in mid-late may predator insects and birds found the smorgasbord and the plants were recovered by mid june when these pictures were taken. My romain lettuce were slighly out of season and bolted but everything was looking healthy and green. The tomato plants are wide/full plants and producing some small tomatoes. The pepper plants were still growing/establishing and I think you can see some squash plants in one of the pictures going nuts.
Brian
