Hydor Submersible Aquarium Heater

I've already written a review, but since I was asked to write another one, here goes. I bought the 25 w for my grandson's Betta tank, as I find it's the best heater on the internet, both in quality and price, and you get the added bonus of having a submersible heater! I might add, if your tank gets any amount of sunshine during the day, keep an eye on the temperature control and adjust accordingly - you may have to lower the temperature setting to compensate for the warm air in your house and the sunshine helping to heat your tank water. Great product, no matter how you slice it!

I bought the 50 Watt for my 10 gallon betta tank (because it's the same price as the 25 Watt) and it works great! It has a wide temp range and easily went up to 85 degrees while treating ich. I even bought a second one for my 5.5 gallon and plan on buying another one for my future 10g. Great price as well!

This heater is a must have for anyone who keeps Bettas in small aquariums, or anyone who uses a 5 gallon tank. It is the best submersible heater I have found and the price is the most reasonable on the internet. I have 5 of them for my 4 Betta tanks and my 5 gallon fry "grow-out" tank.

As the title says, it's my third one! I'm so in love with these heaters... The first one, I have now had for about two years! It is the smaller 25w one, but the fact that it has lasted this long (and will probably keep lasting me for a good while) says a LOT! Most smaller heaters are poor quality, defective, and while cheap they only last a few months... and as a fellow betta keeper, I have come across MANY other betta owners that have bought cheap heaters for the convenience of price and it didn't last them even three months. The second heater, I actually bought for a friend of mine who also has a betta- poor thing never had a heater until I got one for it and that betta enjoyed the warm tropical temperature as much as mine does. I'm only buying my third heater because I recently got another fish tank for a new betta... and I know the hydor theo is too reliable and too great of a bargain to pass it up. Heating aside, it also feels durable. I was originally worried I might break it because it's made out of glass or something that feels a lot like it... but once you get past that feeling, you find that it is indeed a durable little thing. I've accidentally banged it here and there and it still works like a charm. The light is very convenient to know the heater is still working. It's very easy to clean if debree like bits of algae or dirt from your substrate gets onto it, and the fact that it's submersible and has FANTASTIC suction cups means it's very easy to move around and position in your tank. As I said, it's been about 2 years and the suction cups are still working great (and that's saying something for suction cups!) All and all I can't help but recommend this to anybody looking into a heater... I know there are some people that have experienced defective heaters, but I'd honestly have to say it's the luck of the draw from the manufacturer. Definitely dig into reviews and see how many actually deal with defectiveness involving a great quality heater such as this.

Bought the 50W for my Fluval Edge 6 gallon. Heater works great and I like the fact a little orange light comes on to let you know when it's heating. Keeps steady temps and is accurate to 1 degree of my two thermometers. Will buy another when I figure out what I'm going to do with the Fluval 12 gallon I recently picked up for cheap.

I have had this in a Aqueon 2.5g Mini Bowfront for almost a year now and it works great. I have to set the temp lower than what it states on the dial, but that is to be expected due to the small size of the tank. Once I fiddled with the temp setting a bit it holds my Betta tank at a steady 78 deg, which is perfect. I would totally recommend it to anyone with less than a 5 gal tank as long as they knew to work with it a bit to get the temp correct before they state that it is to hot.

I got my order very fast. I started using the heater and it works great, I love it.

Compact enough to fit in corner of my 10g tank to not look cluttered. Nice glassy look and easy to adjust temperature dial. Works great, looks clean, easy to set-up and it generously comes with two suction cups.

The heater works real well and adjusts good. Submersible feature is very useful since our tank has a cover.

I purchased the 300 Watt one for my 55g tank - nice looking heater, stays very neat with the suction cup attachment, easy to adjust temperature, sturdy enough to withstand curious bumps and mouthing from my active large goldfish, and best of all, IT WORKS! Keeps the water nice and warm and my fish happy even though the tank is in the coldest room of my house!