hygger Aquarium Heater,600W/800W Submersible Fish Tank Water Heater Double Quartz Explosion-Proof with Separate Temperature Measurement System for Freshwater Saltwater Tank (800W)

The only reason I give it 4 stars and not 5 is because I currently have little Senegal bichirs that are about 3.5 inches long and one of them was going in to the space in the heaters cover and just chillin inside of it. I had to wrap the heater in some netting to cover the gaps so it would stop going in there. I feel like it’s more my fault than anything just because this is something I should’ve thought of before buying it. Luckily nothing happened to the bichir but it was scary lol. Other than that I do like the heater. It does the job, I like how it looks and I like how easy it is to use.If you have little fish or plan to get little ones that like to hide in small spaces be mindful of the gaps in the heaters cover.

I have these set up on my 135g saltwater reef tank one set at 79 other one 76 so if one fails other one will kick on. Very reliable readings

This water heater is really nice for my 75 gallon tank and works great. The temperature is adjustable and doesn't take much space which is amazing. The fish in my tank seem to love it as well! Highly recommended for heating up the tank during the colder months!

I don’t understand how a heater designed for an aquarium is NOT waterproof at the top. I have to watch it as evaporation occurs to make sure the water line is ok for this product. I missed this fact somehow before I purchased it or I would have purchased a different product

Temperature knobs hard to turnHad heater about 6 months in a 55 gallon tankTemp set at 75 degrees was working awesomeWoke up this morning and heater wasn’t working tank water was at 72 degrees so now I ordered a different heater from another company