got a new heater for my 30 gallon today since the one that came with the tank sucked. within a few hours the temp could change up to 10 degrees. so I got a marineland visi therm stealth. I like my visi therm in my 20 gallon and figured that was a good one to go with again. just one thing I'm not liking is the fact that it has no indicator light to signal when it's on like the original visi therm or my neptune in my 55. just one design flaw I see with it, well to my perspective.