I am in the planning stages

[Morgan Mayfair]

Hi all. I am very pleased to find your forum and all the helpful information I have read here, and so many enthusiastic members. :))

I am in the planning stages of an aquaponics greenhouse, and wanted to run my plans by you who are more experienced for some trouble shooting.

I live in Maine (USDA zone 5) at 400' above sea level (not sure if this matters except that I am not at one extreme or another as far as elevation goes). I live on a gentle hill above a river valley. I am planning a 12'x30' pit greenhouse with two grow beds 2'x 24' and two fish tanks 3'x3'x6' each. One of my goals is to run this system without electricity, as electricity is unreliable out here in the woods (it was out for two weeks in January a few years back). How I plan to do this is to make use of siphon power and gravity - the drawback with that, so far as I can see is that I either have to have my grow beds continuously filling and flushing (the level of wetness may be detrimental to the plants I wish to grow - peppers in summer and brassicas in winter - hopefully) or have to be on hand to do it manually less often.

I would like to raise tilapia over the warm season and overwinter fingerlings inside my home for the next years batch, but I have serious doubts as to whether I can keep the water temps warm enough (I really like those pretty red ones). I will probably need to resort to trout though, and I need to better understand trout care. I have experience keeping fish in a pond, and a fish tank, so I get the principles - filtering, water quality, aeration - and have had to treat some fish diseases.

Anywhoo, I may have to set it all up, and then see what it is capable of experimentally. One other thing I am not sure of is if I can use a pond liner and save myself some money on concrete work, or if liners are too short lived. I have also heard tilapia will ruin a pond liner...

So, any input is welcome - thanks.  

[Glenn]

 Please post more of your thoughts on the use of siphon power and gravity. The circulation of air and water required for about 800gl. fish tanks and 96 surface sq. ft. of growbed can be aided by gravity and siphon forces but,,, are you probably going to need solar, wind, and maybe a little electricity? Perhaps even the 9 or 12 ft. garden windmills that can drive a rope pump and or air compressor.

 

To what density do you intend to stock fish and plants? And how far from the river will your pit greenhouse be?

[Morgan Mayfair]

I'm about half a mile from the river.  I had a neighbor who trekked down there every morning as a kid to fetch water for his family cows, but... well I'm no kid.  

The figures in Sylvia's book say I could get about 200 lbs of fish if I maximized my system.  I thing I will shoot for less, perhaps by half, at first and augment the fertility of my plant beds with "organic" folair fish emulsion spray (how organic can something like that really be?).  Experimentation will eventually show me what more I can do.  

The siphon system I have in mind is pretty simple - a hose from the bottom of the fish tank to the top of a water tank, and a faucet at the bottom of the water tank.  The weight of the water in the tank would pull my fish water up to keep filling the tank as it emptied at the other end, with bell siphons to empty the beds and the splash of an elongated drain pipe(with multiple holes) to aerate.  Probably two of these running at intervals... I need to see what it does to my water levels in the fish tank because I can't quite visualize it yet.  

I have been thinking that a simple windmill to churn water on the surface might give my fish more air too.  Solar heat is fairly easy - when the sun is out.  A little more effort and I could run hot water under the floor for heat in winter.  We heat water with our wood furnace and always have plenty as we heat almost solely with wood (we have a family wood lot).  The use of hot stones also intrigues me, because a stone can be carried to wherever the heat is needed - like the Native Americans and Swedes did (saunas and sweat lodges).  

As a hobby it won't matter if I am great at this, but if I ever need to feed my family, given the current political and environmental climate I think aquaponics could be a very helpful link in the chain - along with my regular garden, mini orchard, berries, etc.  And all of these are skills.  I want to learn now, in case I need this someday.   

[TCLynx]

Morgan,

    I fear you will find that you actually need to pump water a bit somewhere.  The water bridge kind of siphon you talk about with the hose in the fish tank and letting water out of a water tank will only work to keep the water levels int he two tanks equal.  If the water tank is above the fish tank, what happens is the water tank will siphon drain down into the fish tank rather than the water from the fish tank being drawn up into an elevated water tank.  Get some buckets and tubing and play in the bath to help wrap your head around it.

Now you may be able to to an ultra low energy model with constant flood grow beds and air pumps running airlifts just a tiny bit to circulate water but you still need some form of power to run the air pumps.  Also, trout like really good water quality, circulation and aeration.  they might not be the best bet for your first season.  What about bluegill?   They can handle hot and cool and the only real drawback is they are kinda slow growers but they are also quite edible at 1/3rd of a pound.

I've used pond liner with tilapia and catfish, As long as you get the high quality stuff like the firestone pondguard EPDM liner it is pretty good stuff.  However, you still need to support the liner so some concrete work might still be necessary when digging into the ground so some potable water quality pool paint to seal a concrete tank might be almost as cost effective.

If you really want to do warm water fish the ground won't be warm enough so you will need to insulate between the ground and the greenhouse for Tilapia since they like water in the 70's and I expect your ground temp there is probably more on the order of 55 F.  But to me, tilapia are over rated unless you absolutely have to feed them on algae and breed your own fry.  (though you can probably breed your own bluegill too though I haven't tried it yet.)  We actually like the channel catfish best.

[Morgan Mayfair]

I'm not quite sure why the siphon system wouldn't work... hmm.  It would be sealed, with water emptying into the top, an air space and then another pipe/hose running into the grow bed.  I don't see how it could run backwards but I will try it small scale before I go large scale, as you advise.  

Thanks for the info on fish.  I'll go google bluegill now.  :))

[TCLynx]

Perhaps I miss understood your initial description.  It sounded to me like you were saying you would draw water up out of a fish tank into a header tank using a siphon.  Unfortunately, a siphon is going to still drain down, not up.  A siphon can lift water up a bit to get over say the lip of a tank but the end of the hose where the water drains from is still going to be the lower end of the hose.  The best you can expect from a siphon is going to be to keep two tanks level with each other at equal level.  Otherwise you will be draining the upper tank into the lower tank using a siphon, not the other way around.