Looks like you've thought a lot about this. I like the planned use of the already existing pool area. Like I've said before I'm no expert but I noticed a couple of things that concern me. 1. The solar heater in Michigan isn't practical for winter heat. There's not enough sunlight to make any significant difference. I tried one for water in the summer with 200' of black tubing and it hardly made a difference then. 2. If I read this right you don't plan to recirculate the fish water but rather drain it through your garden. Although fish waste is beneficial to your garden you need some sort of media bed to create bacteria to change the ammonia into nitrates for the plant uptake. Plus not recirculating your water will create a need for more heat for the water. Those heated tanks also act as heat sinks. Have you considered a dutch bucket type system?
Yes, I've been researching for a month or so. You're correct about Mich winters are a no go for solar. The wood stove will work for non sunny days. The solar hot air only works on sunny days which will be more Arp-June and Sept, Oct. It draws hot air from the top of the truss and heats water in a heat exchanger. The air temp hits 100+ on sunny day even when OAT is 40-50! What I have read in aquaculture and aquarium forums is the nitrogen cycle is in the fish tank and for a well stocked tank a 10-15% daily water exchange is needed to maintain healthy tank water. Grow beds do produce more nitrates and the sediment tank will also continue to produce nitrates. If nitrates diminish in the fish tanks I can recirc some of the sediment tank water back to the fish tanks or more likely cut back on exchange water and let it built up. I can also water greenhouse plants with well water if needed. Actually recircing the grow bed water back to fish tanks would take a lot more heat, because grow beds are continuously circulating and water would come back cool. The well water will only needed to be heated once a day to about 90 deg 15-20 minutes to replace the 75-80 deg tank water and bring it back up to 85 deg. I'm going by how my friend Gary raised a dozen Tilapia two winters ago in that hot tub using the wood stove water heater. He kept tank water temp at 75-78 with just one heated water exchange a day even when building temp was 32.
Jeff S said:
Have you considered a dutch bucket type system?
The double buckets that wick the water up to the plants? Yep, almost went that way, but decided not recircing the water was better and only one bucket is needed!
I'm surprised you didn't get much heat out of the 200' black tubing in the summer! I thought on sunny days that was a good way to heat water, maybe not. My system is all experimental and I'll know a lot more after doing it. I appreciate the feedback and glad to explain anything.
I have a thermostatically controlled double fan (Menards about $40) in the rafters that's set to turn on at 60 degrees to blow down the warm air. I would get another one but they don't sell fans in the winter. I also ran the wood stove duct pipe at an angle through the rafters from one end of the GH to the other to exit in order to capture as much of the heat from the stove as possible. Got the idea from my 125 yr. old house that used to be heated that way. Are you planning to grow veggies in the winter?
Do you have pics of your GH? It's definitely a challenge and expensive to heat and grow veggies in the northern winters. Ten years ago if I had been into AP I probably would have built a small GH heated by wood stove or pellet stove for MI winters. Now I'm retired and think I'll just go south for the winters and visit some AP places in NM!
Did you have aquarium fish before doing AP or do any gardening? When you started your Tilapia last year did you per-establesh the nitrogen cycle or just let the Tilapia do that? I was thinking maybe I should start an aquarium in the house to establish the nitrogen cycle and speed up the cycle when I get the Tilapia in March. I plan to start with 60-70 fingerling and would like to have the nitrogen cycle already going, lol.
Jeff S said:
Are you planning to grow veggies in the winter?
No, just going to be an 8 month operation. My goal is to stock my small chest freezer with home grown fruits, veggies and fish. I surely can do that in 8 months and still give away plenty of surplus.
Gene, send me your email address and I'll send you a real informative paper on aquaponics that's too large to put on here.
Gene do you have an update on your system?