Aqueon Submersible Aquatic Flat Heater Mini Up to 2.5 Gallons, Black, 5 Watts

Thanks to Walmart for giving me a free month; it really helped me try to save my sick fish—though she is still ill, and I pray for her recovery. This heater is excellent; despite lacking a temperature indicator, it is a lifesaver for fish, especially in very cold homes. I recommend keeping the water level at a minimum of 4 liters to prevent overheating. Another important tip is to avoid covering the aquarium, as this can cause a sudden temperature spike. The heater works efficiently with 7.5-liter tanks. Be sure to follow the included instructions precisely: maintain the water level (refill the tank if water evaporates), do not touch the heater while it is plugged in, and do not remove it from the water before unplugging it. Handle electrical equipment in water with caution—this heater is designed for your safety and the safety of the aquatic life. Best of luck to everyone.

This has been in our beta tank for about a week now. It keeps the water consistent between 78-80 degrees. It small which is great for our 2 gallon tank.

Very small size and seems to be heating without any issue. I would like to be able to see a light when it is on or something, but it is working, so no complaints. I am just glad it was small enough to fit inside my tank without taking up a lot of space. I have a 3 gallon betta tank.

I now have three of these for my fish tanks. they keep it a few degrees above room temperature but they don't get so hot that they hurt the snails when they crawl on them. it's been about 2 months for the first one I bought and it's still working good.

Bought this to use in the BiOrb15 as the one they sell is rediculously expensive. This heater was most definitely bigger than I was expecting but it still fit well standing on a slant, upright at the back of the tank. I thought about burying it but decided to do it this way instead so that the water circulates around it better. My Betta likes swimming around it and treats the space like a little cave.

Literally the only product I will get for my 2.5 gallon betta tank

Very small so its nice for small tanks. I dont like that you cant control the temperature. It kept a 1gal tank in the mid to upper 80s. I need the tank to be between 72-78 degrees. Not the fault of the product though so Id still recommend

just too toyish

This is supposed to heat a container of water. I can plug it in and hold it in my palm and it's barely warm. Totally worthless and a big waste of money. Walmart if you're listening--I'd like a refund.

I placed it in between the gravel in a 2 gallon fish bowl and there was no difference in the water temp. I will be returning and have already ordered a different heater.