I've tried em all, fried em all. Every small (25-50w) heater I've used in a 10g or less has eventually refused to shut off, and brought temps up to dangerously high conditions. Most recently, tonight, I found my 5g lampeye tank resting at a cozy 100º F. Heater was still on, and the fish were hovering next to the filter flow. I've got it down to 90 so far, and it's still coming down. I don't think I lost anything yet, but this makes me so mad. All these automatic shutoffs and safe controllers are garbage. Why can't they just make a heater that fails by NOT working.
argh.
argh.