Fish Tank Aquarium Heater - Adjustable Temperature Submersible Thermostat Heater,25W/50W/100W/150W/200W/300W

Thy work well

I love the twist top and moveable red piece in there. It's nice and sleek, not bulky like other heaters. I have a 10 gallon tank and within minutes of putting it in, the light came on and warmed up the tank. I love the adjustable suction cups too. And for that price, blows the other heater out of the water. I will update if any issues arise.

This heater broke into two pieces after only one month. At first I was upset about the product quality, but did a little research and discovered glass heaters often break if they're powered on and the water level drops beneath a certain point (like during water changes). So that's my fault, though it would've been nice if that direction was included with the heater. Otherwise, it had worked well while I had it and I am glad it broke into two easily retrievable pieces, rather than fully shattering.

Worked well during the Texas freeze. I had three of this 300w units running in a 500 gallon outdoor tiled gunite pond and they kept the water above 45 or so. I had another floating heater, that helped bring the water up to 57 or so but the floating heater is useless IMO, it does not turn on unless the water gets to 35 or so. These ones work non-stop, it will never reach the 80F setting I have. I dont think this will be suitable for colder places. Suction cups are useless.

Been using for about to weeks to quarantine fish and noticed that over past few days the calibration of off. Today I went to feed the fish noticed the fish acting strange and floating side ways when I touched the water it was ice cold. After putting a thermometer in the water I doubt the water was at about 70 degrees when I had it set to 78. In order to get the temp up to about 78 I had to see the heater to the max.however what’s to say it’s not going to all of a sudden crank it’s self up to that temp. These things a very unreliable. I guess you get what you pay for i figures since I was only using it for QT it would be enough but I guess I was wrong. I would recommend to stay away from these as you might loose some fish along the way.

Product came in the mail quick and works as it should. I don't use it in an aquarium. It's used to heat up saltwater for water changes. Probably about 5hrs a week. Works quick for 40 gallons of water

This doesn’t take up a ton of space being thinner and longer , works quickly, and was an affordable price… I came back the next day and ordered a second one

The temp knob is way off. I have my tank at 80* and the knob is set at much higher then it. I've been doing a no fish test run the past week after our beloved Betta passed from temps not staying at 78-80 which is why I bought this heater. It is small and works great in our 3.5 gal tank. It keeps it right at 80 and kicks on and off. I keep it on a corner of my bow front tank so not see looking right at it. The little fake plants it comes with are cute and feel pretty soft plastic so I've kept them in case I change everything out or add more to a tank later since I'm planing on a bigger tank later on.