I put an Otto on the tank, paid a bit more than the guy who got it off the clearance table at Blue Sierra (I paid $50) but it's worth it, no more trouble at all. Also added a small fan-3" from Big Lots that helps with cooling when the lights are on.
Haven't had any trouble since. Probably is the best investment I have made in a while.
i just pulled my german ebo yagermeister heater or whatever they're called out of my sump and was quite surprised at what i found... the glass assembly had come completely loose and water was inside it. pulling it apart i found tons of rusty crap all over the inards. that made me feel really good about my water quality. if its not one thing its another in this hobby,