I am building a 4' tank that will have a separate scavenge tank. I plan on heating only the scavenge side, which will be about 25-30 gallons of water. Main tank will hold about 250-275 gallons of water. Do you guys think I need to have a way to circulate the water out of the heated part of the tank into the main tank to help heat or at least warm up the main tank, or just heat the the scavenge side and spray that water on the top? If I do that, will the water on the top be warm enough for long enough to hydrate the film correctly? Thanks guys.