Review on 🐠 Hygger 500W 800W Submersible Fish Tank Water Heater with LED Digital Temperature Controller - Ideal for Saltwater and Freshwater Aquariums, Fast Heating for 60~180 Gallon Tanks by Stacey Pegg

4 stars because mine completely burned a hole. DO NOT PUT IT ON YOUR SIDE. The company was very helpful and replaced it free of charge. But you need to be sure you see the fine print on the side of the heater. It means not closing a 'hole' I can't see which hole they're talking about. It should be in BIG BOLD LETTERS. I sincerely think I was lucky it didn't start a fire because although the heating element didn't work, one reader read that it was over 90 degrees and tried to get the tank temp down to the 83 I set it to. . I am very lucky that my fish are alive. This is a really great heating element. But be careful. This only happened after 2 months of use. Make sure you hang up a heater. Don't drop it on the floor like me user error. I would give it 5 stars but due to the fine print leading to user error I'm giving it 4. It could be really bad. But again, the customer service was great. I contacted the company directly through Amazon. They didn't ask for the old one to be returned. Super helpful. Update: The seller contacted me and assured me (despite not seeing the unit) that the heating element cannot and would not start a fire. They gave me a full refund and sent a replacement. I'm keeping this rating at 4 stars because it failed after 2 months and apparently burned the unit. What saved this from getting 1 star was the customer service. They refunded my money and sent a replacement. I will update this review in a few months after trying the replacement that was sent to me. I didn't want to risk it but they insisted their heater would not start a fire and that this was the first time they had received such a complaint. I stand by my original statement. MAKE SURE this device does not fall to the bottom of the tank. The fine print says not to cover the hole. I don't know if this caused my heater to fail, but that's the only thing I can think of.