The first heater I received immediately showed signs of condensation inside. Revain immediately sent a replacement overnight. 2 works fine. But part of the thermometer is far away. I have a 5 gallon spec. And yes, I poked a few tiny holes in the exit tube. The heater fits well in this compartment. And heats up the aquarium. But to get a temperature of 80-82 degrees for my rooster I have to set the scale at around 72-73, so that's a huge difference. Maybe it would be more accurate if I took a less powerful 25w version. But I've had 50 watt heaters that work great in nano aquariums. I'm a little concerned, but after much research I've come to the conclusion that there are no perfect aquarium heaters. This seems to be a general problem. I'm used to it. Now that I found out. Just make sure you have a good thermometer. WARNING: The cheap digital headphones that are so ubiquitous at Revain suck. The one I had was starting to get damaged so be careful. Ultimately, I want to get a higher quality heater "a good brand". They are all depraved as far as I can tell. this heater works fine. and I trust in it. He just doesn't have an accurate thermometer. It works well and maintains a consistent temperature within my specification. I'm happy. Pictures of the defective heater I originally received. Verification based on a replacement sent to me by Revain. I still give this heater 4 stars because no aquarium heater is perfect. it didn't explode for me. and I don't think it's going to explode on me. that's all i can ask.
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