have you thought about a wave maker on the power heads it might help as the power heads will cycle and not have a chance to get as hot you might also want to look at a dehumidifier with so many tanks in one room you must have rain clouds forming have you check the relative humidity in the room you could also loook for one of thoses fans that fit in a window they have dual fans and can be set to suck or blow or one of each it would help change the air in the room as for your cats bothering you tanks we have 11 cats (No that is not a typo i meant to type 11) all they ever do is sit and watch and thay are all indoor cats so they have lots of time to go fishing if they wanted too I also had heat problems when I had my 72 gal bow 5 power heads and 2 pumps in the sump hit a high of 94 deg. in the summer and that is with central air in the house When you do a sump plan for external pumps a BIG return pump will and BIG heat.

Hope this may help

Doug

I agree about the wavemaker. It really does keep the powerheads from heating up. We have a MJ1200 in our "water making cooler" and it was keeping the water well about 90 degrees. We plugged it into the wavemaker and now that it cycles the water stays at about 80.