Backyard Aquaponics
A place to discuss aquaponics

This is my soon-to-be (I hope!) aquaponics system.

I'm building a greenhouse in my backyard so I can have my AP system running year round. This winter has been particularly brutal and since I can't move to a climate that's much warmer (because of my ex and partner's ex and kids) I'm making my own warm climate for my fish and plants. I've been doing outdoor hydroponics during the summer for years, but this will be my first aquaponics system. Everything I've read says bigger is easier when it comes to aquaponics so I'm going to just bite-the-bullet and build a pretty decent sized system without experimenting with small-scale like I did when I started hydroponics.

My greenhouse is going to be 26'x48' (7.9m x 14.6m) and made out of twin-layer polycarbonate. I'm in the process of clearing away the 2'+ of hard, heavy snow because I simply can't wait any longer to get my build going! I have access to an excavator and am going to try to dig the foundation, frost or no frost, to get the concrete poured for the foundation/frost wall sometime in April. I figure a flat, solid, heavy base for my greenhouse can't be a bad idea, and I need to insulate away the frost somehow. I think I'm going to try to go down 5' if I can without hitting ledge.

Inside I'm planning a ~180 cf (5100l) in-ground koi pond and about 45' total (13.7m) of 4' (1.2m) wide LECA or gravel grow beds (it'll be several smaller grow beds, not one that's 45' long), plus having a bunch of room to experiment with PVC tube systems and small raft systems and more grow beds if I want/need them. I'll also be putting an appropriately-sized sump tank in the ground.

I haven't figured out the shape of my koi pond. I'd kind of like it looking more like a pond than a tank, although I know that will be infinitely more difficult to build and line. I know I'm going to line it with EPDM pond liner, but what I'm going to have between the pond liner and the ground is TBD. I suppose concrete would be a good idea but I have no idea how to line angled and curved surfaces with concrete. It can get down to -20F (-29C) at night, so I fully expect I'll need to heat my greenhouse and the pond in winter. I have a big propane heater for the greenhouse, and I think I'm going to try to heat another volume of water with solar heat (separate from the aquaponics system so I can get it as hot as the sun allows me to). I'll pump this water through some tubing coiled in the pond to heat the pond at night, when it needs it and when I have the stored energy available. Aside from the frost wall, any additional passive ideas on keeping my fish warm are welcome! Should I have foam insulation under and around the pond? Will it compress and become useless?

I am away from home several days a month, so I'm also busy playing around with Arduino to come up with a monitoring system. I'm amazed at how easy and accessible they've made Arduino.

I'm just so excited to get my system started! It's pretty much all I can think about at the moment!

I would dig out the whole GH down to 5 ft or ledge rock. Put in an 8x16 in footing with vert rebar and form the walls just like a typical house foundation. Then Put in a passive earth heat system. Basically buried 6 in plastic drain tile. You pull air from the GH and blow it through the tubes under ground to heat or cool it. There are a lot of u tube vids with passive heat designs that don't even need additional heat or just a minimum amount of energy/propane. They use the earth, painted black barrels of water and sun to keep it warm. The solar heated coil never seems to work well from my research.

The pink styrofoam designed for under-slab and foundation walls is readily available. Normally it would extend down the foundation wall below frostline vertically and horizontally under-slab the same distance. If you have already received your twinwall polycarb I assume you have a design for the GH.

For the elevated FT I would suggest a thickened slab. A typical slab is 4 in and where ever there is a load bearing wall the slab is usually 8 in. It might not be necessary depending on size and load of FT but it is easy to do and doesn't add much cost.

Awesome, looking forward to the progress pics.

wow....I want an excavator. and polycarb panels.

Thanks folks!

I know I don't have anything real to show yet but I hope to soon as I build it out!

Rairdog - Thanks for your input! I'm sad to hear the solar coils don't work, that's what I was planning. Of course I can do black barrels, easy, for the thermal mass. I'm a little confused about how to use passive earth heating though. I don't understand how they could possibly be used to heat the greenhouse to a temperature warmer than the ground temp. Can I actually STORE the daytime heat in the ground and use it later? I'll google and youtube and research them, for sure, because I should be using the same concept for cooling in the summer! Thank you!

The fish tank isn't going to be elevated, it's going to be in-ground. Should I still put a slab under it? Or that pink insulation?

Here is a link to some good info and ideas on solar GH designs. The passive earth heating would help level out the temp swings and may not completely heat the GH. It would save a lot of propane.

http://www.builditsolar.com/Projects/Su ... se%20Plans

Video of earth battery heating/cooling. I just wanted to point this system out because you have access to track hoe and were going to dig anyway so the cost would be minimal.

http://www.youtube.com/watch?v=cT8Ic2m7voI

You could put pond liner directly on ground without insulation or slab. If you plan to raise tilapia and wanted to heat the tank to 80 insulation would help.

Awesome! Thanks Rairdog!

Still no fish, no plants. But we had a great time knocking down trees with the excavator and getting ready to dig the foundation!

A little bit more to see... this is the corner where my fish tank will end up; the sump tank will go along the left side just past the fish tank. Hopefully there will be a foundation sitting in this hole before too long!

I'm undecided about the shape of the fish pond. Sticking it all the way in the corner will be easiest, using the foundation as two of the sides of a triangular (ish) shape, like a really, really wide ice cream cone (the foundation walls will be the two sides of the cone, the "hypotenuse" of the triangle will be rounded. Making it not at all a triangle

OR I could do a round fish pond, trying to make it as conical as I possibly can.

I've heard that's better for a cleaner fish tank, less dead spots, etc., but it's a LOT more difficult.

Is it worth it?

Opinions?

Thanks!

another view

Tori. Stop putting the rest of us to shame. Are you going to keep white pointer sharks in that pool?

This one will be fun to watch!

Sweet!

When I built my greenhouse I was convinced that the air temp would be the issue but what I have found is if I can keep my water temp up the GBs heat the space well enough for the cooler weather plants (peas, cabbage, lettuce ect) to be happy. No matter how warm I keep the air I still have to heat the water... My issue now after figuring that out is how to heat the water most efficiently...

A thought that crossed my mind was to pour a small slab next to the green house where I could pile my compost for the garden. You could have radiant heat tubing in the small slab and the greenhouse slab under the FT. Then all you would need is a small pump to circulate the water. I think this could provide a good amount of heat to the bottom of the FT.

Anyway, just a thought. I will be following this one. Good luck!

Jeff: The pond is only going to be 180-230 cubic feet (once I decide on the shape!), not THAT big! lol

Aboman: I'm going to be running PEX from my home's hydronic heating system into the greenhouse. I haven't decided how to use that to heat the water... maybe I'll just put a small coil of PEX in the pool, or maybe I'll do a heat exchanger and circulate the pond water through it as needed. The compost idea is clever but I don't have that much compost.

I too was hoping that by keeping the air warm enough the pond will stay warm, but I was hedging my bets by running the heating lines... well I guess it's good I planned for it.

The heat exchanger idea should work great I would think. I like the idea of locating the source water inside where its already warmer than the green house. I had not considered that.

If you encase your heat exchanger (plastic box of some kind) you could just have an inlet on one side of the exchanger and outlet on the other and the hot water raising out of the box should provide the circulation.

I will be anxiously awaiting what you come up with (so I can copy it ).