Review on Hygger Titanium Aquarium Heater: Digital Submersible Heater for Saltwater & Freshwater Tanks - Ideal for Fish Tanks Ranging from 5 to 120 Gal by Miles Barney

Like many others, I have purchased small glass heaters with dials that never regulate the water temperature. I have a 135 gallon tank with a 70 gallon sump in my basement. Even if they say don't do it, I've got it in the swamp. I have a flow rate of about 6 GPM going through the heater. It works so flawlessly in the app that I set it up and I have no problem keeping my reservoir right where I want it with no more than 1 degree of flow. Holds at a fairly constant 76. I made a swamp mount with my goodies and took a picture so you can see how I work with this unit. I have 500 watts, I've been using it for about a month. Couldn't be happier with the performance and build quality. I would recommend it.