Hygger 50W/100W Submersible Aquarium Heater with Digital Display for Small Fish Tanks

Calvin Cheng: It's been nearly 3 years since I got my first heater and it finally died displaying HH error and the heating element itself doesn't work anymore. So I was left with cold fish in the morning.

The other reviews about the internal thermostat drifting are accurate with mines reading 72 at 78 right before it died which would cook my fish if I depended on it.

When it started drifting to down and giving me 80 degree water, I hooked it up on a quality external thermostat and things had been great. I'm buying a replacement for this because the heating element itself is good, just a terrible internal thermometer like many on the market today.

United States on Dec 08, 2023

J. Miller: that aside, it seems well calibrated and is still working. It's in use in a 5 gal. guppy tank in my gkid's room. Don't know how it would perform in larger tanks. But it's sized is perfect for smaller tanks.

United States on Apr 05, 2022

Christine: Put this in my fish tank and it worked great. Turned it up a couple degrees at a time (quite slowly so as to not cook my fish).So far it has kept the tank at a constant temp. The heater was easy to use, easy to install. Sticks great. Only thing thats a pain is that you cant click down a temp. You can only click up until it reaches the highest temp then restarts at the lowest temp. So you have to cycle through it like you would an oven clock. It doesnt actually raise the temp that fast so you dont have to worry about that cooking ur fish. Just keep clicking until it reaches your desired temp. I have one of the sticker thermometers on the side of the tank, it read roughly the same temp that the heater showed it set at (once given time to settle).

Update: its been ~9 months and the heaters temp display is off. Its randomly jumping from 73 to 84 deg.... I keep thinking it has cooked my fish but when I feel the water temp it is only 73 (also according to the sticker thermometer on the side its still 73/74). This is the 3rd time it has done it in the last 2 weeks.... I can reset it by unplugging it for 30sec and plugging it back in but sadly Im probably going to have to search...

United States on Oct 13, 2021

Spencer: I bought this for my Fluval EBI 3.5g Shrimp Tank. It fit beautifully in the back compartment and did an absolute great job of heating that tiny aquarium. At first it had a betta in it, so that's why I got the heater. It was set at 82° and held great. Then I removed the Betta and got Cherry Shrimp, I lowered the temp to about 80° and it held great. Then I started keeping Crystal Red Shrimp and realized they liked colder weather, so I then lowered it to around 74°. I'm guessing it never kicked on really considering my Florida home stays warmer than this. This was maybe 4-5mo ago when I lowered it last.

Then last week, I rec'd some new "rare" Apistogramma's and realized I needed a heater for my 20L. Yeah this was too small but I thought it would help in a pinch! The temp. that night got down in the 40's and my Apistogramma Breeder tanks are in an unheated finished porch. So I put the heater in, set it to 80° and thought I dodged a bullet.

Later that day, I came to check to see how the temp was doing and to my surprise the display was going nuts! It appeared the temp. hadn't changed at all but the temperature display was just cycling through all of the numbers like...

United States on Jan 08, 2021

Collin: 50w works great in my 5g. Does a great job keeping the tank right at the set temperature, with minimal variation. Being so easy to adjust (with the button on the cord) makes it extremely easy to raise or lower the temperature precisely and at whatever speed you want. Being able to creep the temp up over the course of a few hours is exceptionally useful for acclimating new fish, and is a very nice feature in a heater of this price. It's a little bulky: not as long as the standard heater, but wider and about as deep. Makes it easier to fit into smaller tanks, and the black housing blends into a black background reasonably well.

The only issue I've had is the suction cups not keeping it well-secured. If the cord is running in a more or less straight line to the outlet it's fine, but if the cord twists at all it also twists the heater and pops off the suction cups. But with how nice the temperature adjustment is, I don't think that's enough to knock off a star for me.

United States on Jan 13, 2020