Review on UL Listed NICREW Preset Aquarium Heater with Submersible Electronic Thermostat for Fish Tanks by Renae Lockwood

I bought this because of the great price and the fact that it is set to the right temperature. You get what you pay for, I've had it less than a week and some white mucus came out from underneath and the temp was too high. I contacted customer service and to be honest they were very nice and helpful. They sent me a new one that did the same. The temperature was too high for the pool, and more white goo came out at the bottom. I don't know what that white stuff is, but I'm definitely uncomfortable with my fish living in an overly hot tank with an unknown (glue? chemical?) substance in the tank.