Attached is a diagram of a new system I'm building. Comments and suggestions are greatly appreciated.
I modeled the system off a CHOP2, with the addition of an elevated head tank to gravity feed the towers and growbeds, and to also provide a solids waste tap. The bulk of the system will be enclosed in a 13x20' climate-modified (not climate-controlled) greenhouse. A 300 gallon sump with a rock wall will provide passive warmth on colder days. The 625 gallon trout tank will be in a separate, insulated and covered enclosure with a chiller that will probably be used about half the time.
A couple things I'm wondering about:
- Still up in the air about pump choice: in-line or submersible?
- I will have worms in the towers and growbeds so the solids may not be an issue.
- Does anyone specifically send the solids to growbeds with heavy feeders, or do you just let the plants work that out themselves? I'm thinking about the issue of some plants having exuberant green growth but abyssmal flowering or fruiting.
- Suggestions on other warm water critters for the sump; koi, perhaps? Or prawns? I can't eat shellfish myself but they may be a good commodity here locally.
Additionally, I have two rabbits as compost engines and four laying ducks (and a fairly useless dog :-) ) that could either add to, or benefit from, the entire system. I have room for expansion; i.e. extra tanks, small aquariums, another growbed.
Your design is similar to the mistake I made. That is mixing the clean water with the fish water. Note the fish get their waste pumped back in to their tank. I fixed mine in the sump tank by making a divider between fish waste water and clean water with out needing a major change in plumbing.
another no on chop2..
keep the head height in mind for your pump with the header tank, you'll need a pretty good size pump to supply the gb's and get water up high to the tank.. most solids wouldn't make it up to the header tank.
i'd consider using another tank for the towers.. if your towers are media filled (like nate's) you'll have surface area for bacteria.. but if your using pvc type towers with "pockets" you'll need to add filtration
i'm not quite sure what you're doing.. you mention passive heat, but have a chiller....your growbeds, towers and the surface of the tanks will do the most towards temp transfer, with flowing water it will balance fairly quickly unless you don't run the water at night during the coldest months, which is ok, as long as you're still adding aeration, and most fish consume less food..
i'm only familiar with submersible pumps, and will continue to use them..
regarding livestock in your sump.. i've had crayfish (marmokrebs), and currently have rosy red minnows in mine, i raise both for supplemental feed for my yellow perch, bluegill and tilapia.. prawns need lots of space per animal, (as do some crayfish) or will kill each other, you could raise a few prawns, but they need real warm water..
Thanks for the comments so far. I like the idea of raising minnows in the sump--more food for my fish.
Some info I left out:
- I'll be raising trout, hence the chiller on the fish tank. The chiller will help maintain the 50-60F temperature on warm days; our nights are pretty cool here so it will probably only operate part-time, a few months a year.
- I'll be using Nate's ZipGrow Towers.
- I'm hoping that the combination of the heat sink sump and elevated head tank will warm the incoming water from the fish tank enough for the plants to thrive, aiming for 70F.