Suppose I need a chiller?

[Limpit]

I have my 125 gal. set up in the basement. I have 2 Seio pumps in the tank for flow and two (Catalina Aquarium) pumps down in the sump. I have 260 watts of PC lighting in a fan ventilated hood.
Even though the heaters are not on the water temp. with the lights off is staying at 80 degree's. I would like to get things cooled down to around at least 78 degrees. I know that it is a lot cooler than 80 degree's in my basement.
Do you think it is the CA water pumps in the sump that is creating all the heat? They say on the package that they are low heat producing.
With the price of chillers for a tank my size being so expensive I thought I would try different pumps first but don't know if Mag Drives would be any less cooler running.

[Reptoreef]

Is that 80* constant??? Have you tested the temp downstairs and also used another thermostat or 2? I'ld say you're fine even if the 80* is the lowest the temp goes as long as it doesn't rise above 82* or drop below 78*. Check the temp in the same chamber as the pump... and test the temp with lights on.

[Reptoreef]

Oh... BTW, if you have enough room, an additional sump(anything from a 55 gl bucket to a large rubbermaid will work greatly) will add both a larger water volume and more contact time in a cooler area for increased heat reduction... maybe a step like that would aide in savings of the chiller.

[bjpembo]

80 is fine, my tank consistently runs at 80-82 degrees with no troubles. stability is more important that the actual number as long as its not too extreme. have you tried a fan blowing across your water yet? that'll drop your temp by 2-3 degrees, sometimes more.

[dakar]

I second BJ's idea.. with 900w MH over our tank remp were getting unreasonably high, 84+, the addidtion of a 2 4" fans blowing under the 250w bulbs onto the water and a 9" desk fan under the 400w bulb holds the temp dead on at 78 with just the actinics and 80 max with the halides running all day. Keep in mind evaporative cooling while being a cheap way to keep temps in ckeck will increase the tank's daily evaporation so you'll need to mind your water levels a bit more. But $5-10 for the fan(s) sure beats $600 for a chiller, and costs a lot less to run (I just have mine on the timer circuit with the lights.

You said your canopy is vented, can you elaborate a bit, fans in the sides or top? Is the back sealed or open?