Heating my water

[Cash-matters]

Hi, I'm moving on to my 2nd system - a step closer to my aim of a commercial system in the uk. I want to try and heat the water so I am able to grow tiliapia here in our cold climate. What I'm going to try is to use 15'' black guttering pipes as the gb so that the sun heats the water as it flows through. I'm going to insulate my tank so that it acts like a heat store. I hope to keep the water warm enough for the 9 months I need to grow my fish. All inside a polytunnel. Any thoughts anyone ?

[rfeiller]

Make sure the black guttering is non toxic. You may have to contact the mfg for that info

[Cash-matters]

Will do. What do you think about the concept though ?

[rfeiller]

As long as you have a thermostat that controls the heat. Are you then going to contain the heated water at night? The problem where I live is winter is rainy season inconsistent sun, so haven't tried winter solar heating

[Cash-matters]

As long as you have a thermostat that controls the heat. Are you then going to contain the heated water at night? The problem where I live is winter is rainy season inconsistent sun, so haven't tried winter solar heating

I'd plan to insulate the tank so that it retains as much heat as possible. Dont think that I would be able to keep it warm enough throughout the winter but long enough to get a crop of tilipia a year.

[badflash]

You might be surprised by the power of a solar hot water heater. I bought 2 2'X20' solar pool heaters for $75 each. When I tested them they gained 8KW of heat between the two of them.

[Cash-matters]

Yeah, I've thought about the prob of over heating and still not solved it. All I thought was that on the warmest days I would have to remove the insulation and hope the heat dissipates way

[keith_r]

you'll have massive heat loss from the surface of the water unless you cover it..
also the air from your air pumps, are they going to be pumping "cool" air into the water?
and every time you pump the water through the growbeds, you'll transfer heat..

i understand the attractiveness of tilapia, the food conversion, quick growth, easy breeding.. but i'm not quite sure i understand why so many people want to "fight nature" when picking the species they grow...
anyways, i'm looking forward to trying fish that are used in ponds in my general area, which means they're more readily available and tolerant to this area.. trout probably this fall,, maybe some crappie.. but so much is available..
btw, has anyone seen the game fish food for large mouth bass? almost as big as charcoal brickets!

[rfeiller]

I think one of the advantages is they are primarily herbivorous which makes them less costly to raise. If you feed it becomes costly. I kept bass as pets yrs ago fed them beef heart. They grew to about 5 lbs before I put them back in the creek. They grow very rapidly on beef heart. So much of the dry food is filler and produces a lot of poop and slow growth. I know I'm going to get flack for saying it. Worried make a beef heart mix with peas, squash, sweet potatoes, throw in some spirolina freeze it.

[keith_r]

actually, i've been reading about purina's line of Aquamax feeds.. pretty much available at local feed mills, with specific formulas for carnivores, herbivores etc..
50lbs usually goes for around $30 to $35, and they're supposed to provide "complete" diet needs..
lmb has a feed conversion of somthing like 1:10 or 12 so it would be expensive.. one 50 lb bag of feed to get one 5lb fish!
perch isn't bad at 1:2, so for 25 yp, 50lbs of feed will get them to 1lb, (plus "supplemental" feed, minnows, scuds, daphnia, worms, etc)
isn't tilapia something like 1:1.2 or 1:1.5? even if i was raising tilapia, i'd want to use a high quality feed and supplement
here's one i know i'll get flack for, but tilapia at the store is usually no more than $4.99/lb, (during the summer there are local suppliers so its not the "imported from china" frozen tilapia that is $3.99/lb).. yellow perch has been at $14.99/lb for at least the last year and a half