Mini Aquarium Heater 25W Small Fish Tank Heater 25 Watt with Free Thermometer Sticker

I have been keeping freshwater aquariums on and off for almost 30 yrs. Heaters have always been the same tech they are now. The BIG takeaway is to keep them cool and constantly sampling flowing water. I have ALWAYS set mine up by the pump outflow and kept them completely submerged. DO NOT keep them plugged in while changing water. This lowers overheating and temperature component shock which leads to a lot of the issues seen in the reviews here. If you have a betta in a setup with no water flow... do not get a heater until you have an actual tank setup. STOP putting these in bowls and expecting them not to blow up.Temperature accuracy and what I have learned with this unit... I keep mine in the pseudo sump unit in the 5 gallon kit I bought. This way water is constantly flowing around the unit. I have an air stone in this same compartment and when it is running it cools the unit more which lead to it running between 80 F - 78 F. When the bubbler is off it cycles and stays a consistent 78 F. So, over agitation can lead to the unit sampling too cool and cycling more. So, I have put my bubbler on a timer and do spaced out 30 min cycles throughout the day. This has resolved the issue with this unit. It needs gentle water flow for accurate sampling and heating. Over agitation can lead to it falsely reading the water as cooler leading to the varied warmer temps.

Perfect! The temperature gauge you get with it isn’t really helpful but knowing it will stick to the temperature it should be at is comfortable enough for me to trust it without a working thermostat. Just make sure you don’t leave it plugged in accidentally like I did outside of the tank😅, it doesn’t turn off. Completely my fault though.

This heater is amazing!! It fits perfectly in his tank! Came just as pictured, and the light will let you know when it’s set!! Def recommend!!

I'm on day 2 with this is my tank.. it holds the water temp between 78°F and 80°F. So far my issue is with the suction cup not holding to the side of the fish tank. I've had to place it back on the side of the tank twice already. I'm really hoping it doesn't bust, as I've been reading several reviews that the glass tube busts and one has busted the fish tank 😖 if it keeps coming off the side of my tank, I'm going to have to look for a more expensive heater for my black orchid betta.

This is a very nice simple fish tank heater, I use it for when I'm making new salt water for a water change in my reef tank, I do 3 gallons at a time and this little heater has no problem getting the water to just the right temperature.

Works well, stays in place and heats water. have had no problems yett.

As most of you know a heater is a necessity for most if not all aquariums and I recently got into fish and wanted to start off easy so as a beginner does I got myself a betta. My tank is 5 gallons and full of live plants and my betta is thriving. The heater heats up surprisingly well and it comes with a preset temp already so no need to haggle with the heater at all just plug and place into your aquarium. It doesn't take much space and it indicates when it's at the ideal temp with a green light. I would rate this a bit higher but I did recieve mine without a suction cup but have ordered a replacement but besides that would reccomend.

I really like this heater. However, it doesn’t stay on the green light. It goes from green to red throughout the day. Is that how it should work? I was under the impression that when it got to its temperature it would stay on green. Can someone please let me know? I’ve attached pictures to show what I mean. The temperature clearly shows 78 but keeps switching between the green and red.