Hmm, not sure how to edit this post I made.
I bought a 100 watt Aqueon Pro. It turned it up to 88 degrees and it also gets my tank up to 82 degrees and then the light turns green, which means it thinks it's 88 degrees in the tank.
So that's weird.
The thermometer is on the opposite side of the tank from the heater. I'm very surprised that 2 heaters, when turned up all the way, only bring a reading of 82 degrees. If the heat is on very high in the house, I do get a reading of 84-86.
I ordered a 150 watt Aqueon Pro from Amazon just now, because I'm frustrated and I want the ich in my tank to go away!