I am waiting for a new 180 gal glass tank and have not thought about heating it. I have had up to a 70 gal tank in the past but I just used a 300 watt heater. do I use more than one? I guess that if so they go in the sump? I think total volume with the sump will be more than 200 gal. My past tanks allways had " tenacor simplicity" built in fitration, does the water falling in the overflow cool the water more? the sump i purchased has skimmer with pump, bio balls, fuge with light, and chemical chambers and a 1350gph return pump. There is one open section of the sump for "additional' equipment. they mentioned a chiller, but I think i will need heat because the tank is in my basement.