Review on 🔥 Woliver Submersible Aquarium Heater with Dual LED External Temperature Display Controller - 100W 300W 500W Fish Tank Heater for Saltwater and Freshwater by Brian Kumar

I have several thermometers and a second water heater in my aquarium. They all match the temperature I set on this heater so I can really say the temperature is accurate. It worked very quickly to heat the water to the correct temperature of 77 and then shut off. It turns on as needed, and initially you could see heat dissipation in the water as the water heated up. The suction cups were difficult to attach to the heater at first, but one day they held onto the tank well.