heating

[chalky77]

Hi

What would be a good way to heat my tank? as I live in Canberra and it gets very cold here. It holds about 1400L but is only about 30-40cm deep?

Thanks

[RupertofOZ]

1kw titanium heater... :D

[RupertofOZ]

Why do you want to heat your tank??

[RupertofOZ]

Worried that your tank is very shallow.... you could just about empty it filling your grow bed(s)

[chalky77]

Hi
Im wanting to heat it as it is quite shallow and the temperature here in Canberra in winter can often get below zero

[RupertofOZ]

Far too shallow IMO.... and pure physics says that to raise the temperature of 1000L, by 1 degree... requires 1kw of energy....

It would probably be cheaper to move to Cairns... :D

[davidl]

Far too shallow IMO.... and pure physics says that to raise the temperature of 1000L, by 1 degree... requires 1kw of energy....


not quite right Rupert, it takes 1 kilojoule of energy to raise 1000L of water 1 degree. A 10 Watt heater could do that in 100 seconds if no heat was lost to the outside. The problem with large surface areas is the rate of heat loss to the outside is very high. If you can insulate enough, and cover over the tank with insulation a "small" heater will be enough. You just have to watch out for blocking off the aeration.

remember to insulate the grow beds too.

This same problem of heating lots of water is also a benefit, in that it takes time for the night to cool the water down from its day time temperature. If there is enough insulation it takes longer than the night to cool down too much.

To heat up the water during the day lots of people use solar heating by pumping water through long black pipe coiled up to a large surface area facing the sun like in http://www.youtube.com/watch?v=S87KDpEUzfE
Though you don't want the water flowing through the pipe at night.

[RupertofOZ]

You're correct David... 1 kilojoule....

But sorry... even if insulated... a 10w heater just wont hack it...

I've run 2 x 300w Jaegars in 1000L tanks... in an insulated garage... and barely maintained temperatures...

You're right about the thermal heating/cooling effects... especially in a body of water that has a large surface area vs depth...

And that was one of my reasons for saying the tank was too shallow... the other being that it's going to be difficult to configure such a tank to prevent draw down of the tank volume... when filling the grow beds....

As to heating the water during the day vis solar and poly pipe... yep... it works... but what you gain during the day... you lose throguh the night anyway...

Unless the tanks and grow beds are insulated... and you don't draw cold night air through the grow beds... i.e no overnight pumping.... and you don't get crystal clear winter nights... etc etc...

I really can't recommend trying to heat a system in Canberra... it just makes no sense....

Stock trout during the winter instead... and save the money...

Even if you can heat and maintain some temperature in the tank.... unless the temp remains above 16-18 degrees... most other fish wont eat, and/or grow anyway....

[Walks-In-Storms]

I'm perhaps "butting in" again, but the problem of heating and cooling seems to me to come down to what I finally had to do - a simple greenhouse. There, the temperature ambient to fish and plant water becomes one of getting temperature where it's best, then maintaining it. More, one then has choices he wouldn't otherwise have, and as many as are feasible. The other consideration is that of hobby or necessity. If one is doing aquaponics for fun, expense is one thing, if - like many of us in the Land of the Free (and stupid who elect people like Barak Obama) - it's about assurance of a food supply, it's another.

I liked the reversion to science and math, by the way.... Well done!

[davidl]

But sorry... even if insulated... a 10w heater just wont hack it...
...
I've run 2 x 300w Jaegars in 1000L tanks... in an insulated garage... and barely maintained temperatures...
...
Stock trout during the winter instead... and save the money...


oops, I forgot to highlight that a 10W heater won't hack it. This is due to your system losing heat at a rate much greater than 10W. That point about 2x 300W heaters in an insulated garage, says to me you'll probably be losing heat at a very fast rate. You'll probably still be losing heat at a very expensive rate even if insulated.

I agree, stock trout in winter in Canberra, but what do you do in summer? I thought the idea was to, in addition to trout in winter, have some sort of fish that won't die in a Canberra winter, but grows well in the Canberra summer.
Can Trout survive a Canberra summer if you shade your system?

Looking at http://www.bom.gov.au/nsw/canberra/climate.shtml I can't think of too many options for what to do.

[RupertofOZ]

oopsThat point about 2x 300W heaters in an insulated garage, says to me you'll probably be losing heat at a very fast rate. You'll probably still be losing heat at a very expensive rate even if insulated.

I should add, that although the garage was insulated, the tanks were not... and I was trying to maintain a mimimum 20+ degrees... to over-winter some Barramundi...



I agree, stock trout in winter in Canberra, but what do you do in summer? I thought the idea was to, in addition to trout in winter, have some sort of fish that won't die in a Canberra winter, but grows well in the Canberra summer.
Can Trout survive a Canberra summer if you shade your system?

Looking at http://www.bom.gov.au/nsw/canberra/climate.shtml I can't think of too many options for what to do.

Yep, that's the problem down this way.... just a bit too hot during summer to keep trout all year round.... not hot enough, for long enough to do Barramundi.... unless you can get stock of the right size early, and the summer starts October... and maintains through to mid/end April....

Jades might, might... be an option... but again it depends on availability... and the summer...

The only alternative... is either two seperate systems... one with trout/goldies... and the other with Silvers....

Or just go Silvers all year round...

[redscotcheye]

I like Mr. Walks idea of simple solutions.
I've some experience plumbing and heating, but even a novice can do this. I also live in a cold climate. I'd avoid electric heaters altogether, $$$. My low cost idea would be to use a wood stove with a heat exchanger attached to it. simple copper tubing around the base of the stove and also you could run the copper around the flue pipe. you'd also need a circulator pump and a themostatic controller. Don't run the FT water through the coil, because of the copper. I think having another coil (PEX) or stainless heat exchanger in the sump or GB would be safer.

http://www.motherearthnews.com/do-it-yourself/woodstove-water-heating.aspx

I live in PA where some of us still burn coal (EPA be damned), which is nice because you wouldn't need to feed the fire every 20 min.

[aedwards]

I have a 300 gal IBC tank in my AP system. i have it in a polly tunnel greenhouse. the winter is usally around 40f dips to 30 some times. I was thinking of doing Tilalipa. any thoughts on the mose efficant way to keep the water at temp?