Any ideas on cost effectively heating a 1000l tank outdoors

[Stealth]

We have a 1000L tank outside that does very well in summer time but now with winter on the way we are looking at a cost effective way in keeping the water at a constant 24-25'c without spending 100's of $$ on electricity bills.

All ideas welcome.

ps: The tank is in a 2mx2m green house.

[ryanjury]

This thread may help you..

viewtopic.php?f=3&t=44876&hilit=heating

[David R]

The only thing you can do to make it more efficient is to stop it losing heat, either by insulating the tank or insulating the greenhouse.

What is the greenhouse made of? Do you get big temperature fluctuations with a small greenhouse over summer?

[smidey]

the best way would be to insulate so the tank isn't loosing the heating applied.

i would go for polystyrene sheets around the tank.

[spoon]

http://www.reuk.co.uk/Solar-Greenhouse-Heat-Sink.htm have a read of that apparently its quite effective and may help reduce the time interval that the heater is on . possibly running pipe on a pump thru the glass as well may help this guy made a amazing outdoor aquarium heated and cooled in part by a thermal mass (think the above system but with water there used to be a huge article and heaps of pictures of how he did it but now you have to donate to see it heres the link perhaps email him and ask if you can see the article http://www.wizardscave.com/aquarium.html

[Ira]

Move to the tropics. Otherwise there's nothing you can do that will be cheap...