Am I just missing something or what, I CAN NOT GET THOSE DANG SUCTION CUPS TO HOLD!!!!!!!!!!!! I stick them on and walk in 10 minutes later and their the dang heater is floating in the tank! Am I doing something wrong or what? I had ones that just clamp to the side of the tank but since I am getting a bigger tank and they seem to no longer make any the style I like for that size aquarium.*thumbsdow