I was wondering about these in-line heaters. I notice the largest is rated for is a 65 gal. I have a 75 gal and dont feel I could use just this heater b/c it wouldnt be big enough. What would I have to do, put another heater in the tank, since this one would be plumbed to the canister filter? This would kinda defy getting the heater out of the tank. I am trying to go for less equipment in my tank.