External pumps really add that much heat?

[banditpowdercoat]

OK, I'm still having heat issues on my 150g tank. I'm wondering if it's pumps? The 45g seems to stay at 78 and need heaters at night, where the 150 is still up to 80+ during day, and maybe 78-79 at night. heres the lowdown on them


The 45g has
1 mag 350 run external
1 quiet one run internal
1 Ehiem 1040 run internal
1 Koralia 2 powerhead
4 24W T5 lights


the 150g has
Dolphin AmpMaster 3000 external
Little Giant 4 Mqdx external
maxi-jet 400 and 900 on skimmer, internal
2 150W pendants
1 250W pendants

Both tanks are open tops and closed up sump cabinets. Except the 150, I have to keep the sump door open or else it won't cool past 79. I know the act of pumping produces some heat, but there is little head on both pumps. Could it just be the sump cabinet ambient heat? I do have a 4" computer fan sucking air into the sump where the pumps are, and another 4" blowing down across the sump water. Also, there is a 6" clip on desk fan that comes on/off with the lights on top of the tank.

I'm just loosing over 1g a day on the 150 and it's causing alot of moisture in the house. If I cover tank to reduce evap, then the temp climbs... can't afford a chiller, nor do I have space for one.