I have a 200w Visi-Therm Stealth heater in my 29g. Overkill, I know, but I'd like to be able to move it to a larger tank down the road if I choose to upgrade. I've noticed that it collects bubbles on the bottom half. On a black heater, these really stand out, especially against my black background. Is this just the nature of the beast or is there something I can do about this?