Please tell me about your experience with these. Rumor has it they overheat your tank. I ordered 2 of the 250w heaters by mistake I meant to order something else. Im trying to see if I should sell these or just use them. They are still in the box if someone would want to buy them. I paid close to $60 for the pair i will sell for $45 for both of them. I think they are best used with a seperate temp control system much like a medusa.