What size heater for a sump

[Bad Inferno]

OK,
Built my sump out of a 24" tank and would assume having it about 8" full when running. I have installed a baffle 4-5" high between the pump section and bio area so that the heater is it will never run dry.

I have only two 30" tanks (220 L total) which will have 2*200watt heaters in each tank that will be feeding the sump.

My question is about the rating of the sump heater in watts ? As I assume the water running into the sump will never be 28-30 degrees by the time it gets to the bottom of the sump the heater would be continuously on. For this ever changing small capacity of water should I go for 100 watt heater or higher/lower

:?:

[flukes]

They say a watt per gallon, but because of the water moving through the pipes it does effect the water temp.

Also the watt per gallon rule is for general fish keeping and discus like warmer temps compared to most fish.

Id say you would be look at 2x 150watt heaters. With my heaters for sumps iam looking at the heaters that come with a seperate probe, so your can have the heater in the sump but it reads the temp from the tank.

I think it was Chris that meantioned these heaters and i have been meaning too do some research on them but i couldnt remember the brand he said.

[Chris McMahon]

I use Hydor external heaters myself. Unfortunately they sold out where I got mine.

These (http://www.aquariumproducts.com.au/prod874.htm) look like a good 2nd choice.

[flukes]

All i want is so the heater will be in the sump and it will read the temp from the tank. I am not sure what its called so i dont kow if that model you meantioned has it.

[Chris McMahon]

All i want is so the heater will be in the sump and it will read the temp from the tank. I am not sure what its called so i dont kow if that model you meantioned has it.Did you see the picture in the link? It looks that way to me.

[Bad Inferno]

As my setup is in the garage I am very conscious of the running costs thus looking for the most effective setup.

Kind of like the idea of having an inline heater on the return to the tanks as I think heating the water up to 28 degrees just before tank entry would lower the intank heating requirements. With multi tanks on one sump makes life a little difficult with the sump heater your talking about. (If for instance I isolate the tank with the themostate installed.) Also with the small volume in the sump I think the pump is only rated for submersion into water at 30-35 degrees so a heater with an external thermostate may drive the temp in the sump outside the pump temperature parameters.