HITOP 25W 50W 100W 200W 300W Adjustable Aquarium Heater, Submersible Fish Tank Heater Thermostat with Suction Cup (50W)

This heater has done a fantastic job maintaining my desired temperature range. I read some reviews before hand complaining about it holding a completely different temperature but I’ve had zero issues with mine.The only issue I have is that the suction cups come loose over time. Not enough to where the heater is free floating but it will slide around. That is an easy fix though. Would buy again.

Works great heated up my betta's tank just like the description said! He's been swimming real good, especially now that he's not freezing his tail off!

This heater does really well at keeping my 10 gallon fish tank at the proper temperature. There’s a dial on the top to adjust the heat as you need. It’s kind of big but that’s okay since it gets the job done well.

This has worked so good for my betta fish! I had first got a kit that had a heater with it and after 3 weeks the water was still so cold, my betta had lost his appetite due to the temperature! I decided to buy this and it has been a complete life changer for me! My betta has a huge appetite now and swims freely and with spirit! I’m not worried about him anymore and it works very well!

I have been using mine for three months and it has not failed me yet. Keeps my water perfectly in range. No cracking or shocks.

Works well. Great adjustable for great price. Bought a second for an additional betta tank.

Got this for a 20 gallon tank. The knob is excessively difficult to turn, but no matter what I set the heater to, the water temperature is never consistent. The other day, around 7am, I went through setting it up and getting the heater added to my office aquarium. I just have a mystery snail in there right now, so I figured I'd set it to 76 and see how it went. By noon, the water had hit almost 80. I thought at first that maybe the thermometer was wrong, but no - genuinely warm to the touch. And since I placed the heater and thermomenter on opposite ends of the tank (HOB filter in between) it may have been higher. So about four degrees too warm? Turn it down four degrees, right? I turned it down to 72.This morning the tank was 64 (or less; that's just as low as the temperature sticker can read). Puzzled, I bumped it up to 73. The light turned on and i could see the ripples as the water began heating. As of right now, 1:30pm, it's now sitting between 76 and 77 (climbing). I've checked the tank multiple times throughout the day and I have not seen the heating light turn off even once. If it goes past 78, I'm gonna unplug and return.

The heater works really well. I was unsure about how it worked that’s why my tank was so hot at first the thermometer strip surprisingly works good too I have a regular one and the strip one seems to show accurate temperatures