Aquaponic Gardening

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I'm Building an aquaponics poly-tunnel in my garden as soon as spring is here! I have tilapia and I live in England so I'm trying to think of a 'cheap' way to heat the water outside for them, one idea I have is to insulate two tanks then use refrigeration to cool one tank(for cold water fish) and generate heat in the other tank(for the tilapia/hot water fish) something like in the example picture... has anyone ever tried this before? please feel free to discus this and add any comments(especially if you know something about refrigeration) thanks!!!

Refrigeration with more detail:

I'm even thinking of using scrap/non working fridge-freezer as part of my final design(thanks to google warehouse for the idea's)

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Cool designs...  is that a freezer for the cooling element.  I have found that if you get to complex in aquaponics that the economics get out of whack for you.  It would be good if you talked about what you want to grow and the fish you want to have for your local area,  When you start to incorporate refrigeration and greenhouses the cost of production will be out of line with making  a profit.  If this going to be a hobby venture that is one thing, but if  you want to go commercial at some point in time then  I think the economics will not work for you as you will have to many high cost elements to make it profitable.  That is the problem with aquaponics and marketability of crop options at the present time. Once someone comes up with a viable design that is better than conventional agriculture then we will as aquaponic growers will have a competitive advantage in the market place.   In my mind it is all about markets and profit if not then it is a hobby.

Very cool idea I like the design too. If the point is too prove the idea and you have the cash...go for it! I guess words like 'cheap' or 'expensive' are all relative and subjective anyway...Personally though, if I wasn't trying to prove an idea, or 'see if something would work', I'd probably just take the boring (and cheaper) way out and choose a location appropriate fish. You may find it a drag to be heating water to 70-85F degrees in the winter, in England for Talapia. (Unless of coarse you just really, really like Talapia and don't mind spending the money, in which case go for it)!

Also many people will alternate between 2 or more species of fish, winter/summer...If your good you can grow out trout to plate size in about 6 months.

I rather hope that you do want to prove a concept design and build this, as it is interesting to me personally (this could have implications for some high money fish species, Salmon for instance... the landlocked, freshwater varieties ect)...

Portable Farms™ SALMON Aquaponics Systems

these guys are talking about a simalar system, but I can't find any pictures of the 'system' they talk about, Vlad Jovanovic you kinda jumped my gun,lol salmon are going to be on my list for sure too!


the requirements to heat and cool the water have been greatly reduced by using this modified aquaponics system.

^ some commercial fish safe heat exchangers are available

copper heat exchange would be a big no! I don't want fish full of heavy metals! so i will have to find stainless steel

and of course non toxic refrigerant gases

I'm not saying this system can generate all the heat i need for tilapia, but I am hoping this should reduce running cost quite a lot :D

Yes, but if I remember correctly that guy from portablefarm was talking about over $150,000 USD in just set-up costs, and I think like $30,000 for a "small family system" set-up. I think that this was just equipment costs but am not sure. No-one has been able to find pics or any info on that particular system. I'm sure that it could be biult for much cheaper though.

This may be of some interest to you, though I have to warn you there is a bit of mud-slinging (justified or not) at the beginning of the thread, but if you can wade through that Averan brings it back around and there is some good info for you, or anyone thinking about such a system...

Yeah copper's sure is a big no no...Probably would kill your fish right quick. Titanium may be even safer, but is yet another expense, or if you use a design where no metal comes into contact with the fish water...

Cool stuff, though I'd hate to have to feed that thing. (It's about -17 outside right now). IDK, I guess maybe because I don't consume fish I am biased. Figured I'd go with a native Carp for my fertilizer maker...And I know how fast I go through LPG in the greenhouse when cranking out 170,000 BTU's...It seems many folks in temperate climates have given up on Talapia and have chosen a more suitable species, when not able to take them indoors in the winter months (and even then). Ad to me at least, it makes sense. Just too darn expensive to cater to their environmental needs. It's a tropical fish for cryin' out loud, and wasn't even that tasty from what I can recall...Anyways...

I take it the brick wall side of your poly tunnel is the north wall? You could do to skip the poly entirely on that side and insulate with any number of materials. Or better yet, a connected lean to type of thing. Hehe, have everyone in the Bldg. connect their dryer vents to the GH in exchange for some salad...

Beware the humidity from the dryer vents though

Heck, I'm in Florida and I've given up on Tilapia!!!!!!  I had lettuce cycles hanging from my towers at market this morning, Dang it was chilly to be sitting out there!!!!!! 

If you have good reason to be chilling water on one side and heating on the other, using water to carry the heat away from the freezer or something like that can help the efficiency on the freezer but I don't know if the idea will be efficient enough to really make say growing trout and tilapia in the same system cost effective unless you are getting a really premium price on the fish.  Tilapia are fab for growing in the right climate since it could be possible to feed them from natural sources (if you have the space to do it) but there really isn't anything all that special about them other than that.

When being fed commercial feed, there is very little flavor difference between say Catfish and Tilapia.  About all I can say as the difference between them is if you over cook the catfish it gets tough/dense and if you over cook tilapia it gets dry/stringy, more of a texture difference than taste difference.  They are both very mild and take on the flavors you cook them with.  My Channel catfish in a system that is unheated in Inland Central Florida grow faster than the tilapia did.  In two years of growing both types of fish, The biggest tialpia we got was 2 lb and the biggest Catfish was 10 lb.  The tilapia averaged between 8oz-1 lb after 12 months of growth in my system and the catfish averaged 3-6 lb after 12 months in the system.  The Tilapia quit eating when temps get below about 70 F and they die when temps get much below 55 F.

The Channel Catfish quit eating about 55 F and I've had them in sub 32 F water.

I think carp can probably do very well in comparison to the Channel catfish through I only have a few goldfish and one Koi to really give me any carp experience.

I don't think anyone has seen a picture of a portable farms system. I know many have searched for it though. He sells you a license to build his system. With some research I think you can find all the info you need. You should be able to buy/build the system without a license just fine.



Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pumps and refrigerators. A heat pump is a machine or device that moves heat from one location (the 'source') at a lower temperature to another location (the 'sink' or 'heat sink') at a higher temperature using mechanical work or a high-temperature heat source.[1] Thus a heat pump may be thought of a "heater" if the objective is to warm the heat sink (as when warming the inside of a home on a cold day), or a "refrigerator" if the objective is to cool the heat source (as in the normal operation of a freezer). In either case, the operating principles are identical.[2] Heat is moved from a cold place to a warm place.(wiki - Heat pump and refrigeration cycle) just as I thought it's a bit like a speaker/mic the system can be made to heat and cool

Even your refrigerator can be thought of as a heater. Go stick your hand on the back of you refrigerators metal coils...

Ground source heat pumps take good advantage of this same principle, only in reverse :)

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