Backyard Aquaponics
A place to discuss aquaponics

an open question and sorry if it open a can o worms, ut are there any concerns with the bromide flame retardants used in most foam if they are used as floating rafts?

I can't wait to see your system pictures as its build John. I for one like the tank in the ground. In north west Iowa I think I'm in zone 2. I can tell you your fish water will get to hot in the summer so you'll need some way to remove the heat in the summer. YP don't like it above the mid 80's best for em to grow is 75-77 I think I have read. Winters they dont care the water gets cool buy they dont mind.
So youll fight the heat and fight the cold.
First I like your double skin green house that may help alot on the heat retention.
If I had it all to do again I'd go...
1.With a shed to keep the fish tank in, easier to control their temps.
that way.
2. Split my green house down the middle length wise and construct half using brick etc to hold the heat in the winter.
But you dont care about that you want thoughts on burying or not the tank.
I'm not really to focused right now I have been eating out of my aquarium again. Think I'm at the $230.00 per salad now.
Plan, plan and plan before you build.
Do you have a site picked out and when?
What type of green house? Kit? Will it have vented sides for air flow?
I do so hope you raise YP's. I need someone to figure out how to breed em.
With that in mind do you plan on just growing them out or breading as well?
With my YP's I dont expect to eat one for at least 18 months.
Anyway good luck laters.

Well I was planning a kit greenhouse very similar to yours but this one was 12X24. Ihave reconsidered that after seeing the issues you have had.

I do have the site picked out but I need to check with the county to see if I need to pull a permit for this.

Yes deffinately on the vented sides since we get a few weeks of high nineties here in the Summer. How does warmer water effect the YP ? I may have an issue with that for a few weeks in the summer. I am planning on a retractable shade over the end of the greenhouse where the tank is, I am hoping between the shade and the ventilation that I can keep the temp in the tank managable.

I am sure I will breed them if in fact I go with Yp. I am certainly leaning that way but a lot can happen by the time I get this all built. As for when, I will have the $$$ in my account next week to pay for everything so i will start as soon as I get with the County about permits. Time to work on it is tight since I own a business and need to be there all day, so I will be a weekender for awhile.

How many fish are you down to? I think I saw 31 at last count.

steve, excellent question. I rang foamex when I started using it, and he said they use a polychlorinated cyclohexane which was considered safe for humans. He couldn't say whether it was safe for fish, but it was considered benign by German environmental groups.

John, YP stress then die in warmer water I can't find an exact temp for a death zone but think its safe to say the mid 80's would be the start. Of course in the wild they can just swim deeper during the summer months.
Yep best guess is 31 going by the body count and subtracting from the orignal total purchased. I have tried several times to do a head count, but they keep moving.
If I recall correctly the inside of my green house was up to 120 a few times without the shade cover installed and just four roof vents open, that also brought the water temps to the 90's.
I so need a side vent and am looking at removing one or two panels and installing a curtain unit.
Fully understand the time issue you've alot of work ahead, I can no longer count how many times my design changed from original. Ap seems to take on a life of its own but so rewarding.
Ohh, and what business are you in?
BOL

I have been in the automotive and commercial Window Tinting for 21 years. Originally in Denver and for the last 4 years in Idaho.

Spose your a Broco Fan then?

Of Course!!! And yes I had a GOOD New Year.

As far as the summer heat goes with the fish. I saw a suggestion in another thread about covering your tank in the summer with tin foil, or in your case I'd suggest getting a white pvc draping and just hang it from the edges of the tank.
If you're planning on adding black paint to the back wall of the GH then also consider getting green or red draping to hang in the summer. This will reflect whichever lights would be best for your particular plants.

John, I have been reading along. Have you already built your greenhouse? I read you had two layers of polycarb or mylar about 4" apart, then I read you are considering a kit (I am confused between these). If you still have the opportunity to change the spacing between layers, you might want to have them spaced less that 2" apart. Further apart allows convection to create an air current that reduces insulation. I have read 0.5 to 1" spacing is best. As I said, do not know if you still have an option. A big tank in the ground and in the shade would take over a month of high nineties before the water got too hot. That is why I chose to put my tank in the ground (gravity feed from the grow beds to the tank was a bonus). I also notice that transpiration and evaporation increase a lot in very hot weather. My makeup water is about 50F which probably helps a little. My water depth is 4' and the perch can head down with the catfish when it is hot. At least that is my hopes. I start up in the spring with catfish, yellow perch, and blue gill.

Do ponds in Chicago really get too hot in Chicago? After a week of 40s (100F) no pond I've seen in Melbourne has been much above 20.

I think the temperature of an open body of water is more closely aligned with the wet bulb temperature, rather than the dry bulb (for obvious reasons).

Doug, The greenhouse is in the planning stage right now. I was considering a kit like Got Fish has but have decided to build my own. With 2X4 construction I will have approximately 3 1/2 inches between layers of lexan.

I agree that a burried tank will keep a more constant water temp however I want the heat stored in the water to keep the greenhouse warm enough to sustain plant growth year round with as little supplimental heating as possible. So I am willing to have water temp fluctuations to reach the goal. Yellow Perch can deal with the cooler temp swings but I will need to deal with the heat issue in the summer, don't want perch stew prematurely.

Hummm... perch stew.... there's an expert (apparantly) on perch stew somewhere in this forum ..... LOL

I love this kind of discussion! I am anxious for other opinions. We all gain from other peoples view points!

1st the lexan. Two kinds of lexan to choose from. I chose 8mm double wall which has ribs runing between the layers. Sealed on the top with metal tape and running in a plastic channel. Bottom sealed with permeable tape (breaths) also in a plastic channel. This has worked well and has about R=2 insulation rating (glass is less than R=1). The other choice for lexan is flat sheets and the air gap is set by you. That is a good choice also. The outside sheets will meet over support members 2x4. The inside layer can be cut down to fit between the 2x4s. These can be placed any distance from the outer lexan by using strips of wood nailed to the sides of the 2x4. So, you get to pick the spacing. Tests have shown 1" is about ideal because wider spacing starts to have significant loss of insulation from convective air circulation between layers. BTW, 0.75 inch is about the same insulation and that is a standard wood dimension. These are just items for your consideration.

I only have the single layer of 8mm double wall because winter light levels are very bad in Michigan (cloudy most days in december and january). I will see whether I need more insulation and consider how the light is working out. That will decide whether I add another layer. R=2 is not that great.

Item #2 To bury, or not to bury, that is the question...
I agree about using water temp to heat inside air. But I want to decide how much and when. When the water from your fish tank circulates thru the grow beds that is a large heat exchanger into the greenhouse. You decide how much circulation you do to grow beds and that determines the amount of heat exchange. A control freak, like myself, loves this control. I would let the max circ during icy cold nights and save my plants from frost byte. The same control applies for summer heat. LOVE THE CONTROL! My massive concrete tanks with 3000 gallons of water can hold a lot of heat.

I also am installing a heat exchanger that I am designing from copper tubing. The cold here made me decide on antifreeze in the exchanger. So it is not tank water in the exchanger pipes. I will use 4 ten foot 1/2" tubes in the tank and six 1/2" tubes in full sun. A very small pump moves water to add (or subtract) heat from the fish tank. Because I am using an embedded control computer running from my 12 volt batteries, I have a lot of capability to use software decision making for when to run the pump. My whole system runs from deep cycle 12 volt battery bank. Where I need 120vac, I use an inverter. If you use inverters that are close to the amount of power you need (not oversized) you get about 85% conversion efficiency. Someday I want to run from solar panels (when they get cheaper). Meantime, I have power loss backup. The 120vac is always keeping the batteries well charged thru my Xantrex C40 charge controller. If the 120vac fails, then I have the batteries to run everything. The embedded control computer will see the power failure and adopt a power conservation strategy (duty cycle pumps, etc).

Well that is a bit long winded, but gee, I sure enjoy talking or writing about AP!

This is all theory; I start operation this spring.

Sounds cool!! You're putting a lot of thought into your specific climate, too. Gotta love it!