EHEIM Jager Aquarium Thermostat Heater 100W ( Pack of 1)

A must have for your aquarium. Works great but must clean your heater every month.

The quality I expect from Eheim. Great heater! Thank you

I’ve been using cheap tetra heaters for a while but had to retire them, so figured I’d try Eheim. It’s ugly and I can see it shining through from behind the plants (it’s pretty thick foliage too), but right out of the box the temperature was spot on. It does fluctuate a bit at night and at the warmest part of the day, but it’s only by 0.2 to 0.4 degrees so I’m cool with that. Just know it’s gigantic and very shiny so it’s not for aesthetics. It’s a beast of a heater, more than twice the size of a 100W tetra heater. I will update this review when I have to replace it.

Works great. Very reliable and still going strong months later

I used to use a different brand, I think it was Tetra but their heaters got bought by a different company. So I decided to go with this Eheim. Reason are is because it's just a simple heater. I didn't want a microprocessor controlled one because in my opinion, it's just more stuff that can break. The other reason was because a heater (once again in my opinion) is probably one of the (if not THE MOST) important accessory in your aquarium and should be something of good quality. I've had friends that went cheap on heater, and of course over time, they failed to the point where they were stuck in the heating position and cooked most of the things in their aquarium. Oh, and it was less on here than at the "P" stores. The Tru-Temp feature is pretty cool, so you can adjust the arrow to make the dial more accurate. I compared this heaters temp to a Fluke thermometer and it was .3F off from the factory position. Which for me is more than good enough. So yeah, I highly recommend this heater to anyone that wants a good heater.

Works well with my 36 gallon. Glad I went with this one.

First one I received was heating so high above the set temperature that I maxed out the calibration adjustment and it still had to set it two degrees colder than the actual temperature (I had it set at 73 but the tank temp was at 75). I figured I'd just keep it like that, but then like 3 or 4 days later the temp suddenly started dropping, to the point where I needed to crank it up to 77 to keep my tank at 75. At that point I returned it for a new one. I've been using the new one now for about three or four days and it's working perfectly. Calibrated it the day I started using it and it has held the correct temp since then. Will update this review if anything changes. 12/24 - downgrading to 3 stars after using for a while. Yesterday I tried to bump the temp from 75 to 76 which seems like it should have been straightforward. Moved the dial 1 degree warmer but tank heated up to 77. So I dialed it back about 1/2 a degree and it stayed at 77 (heater was still kicking back on when temp was at 77. Then I moved it down again maybe 1/2 degree or so, and it then wanted to stay at 75. After fiddling for a while I think I finally have it stable at 76 -- with the dial reading 75. Seems like this should not be so hard. Halfway through all this I remembered the directions saying to unplug before adjusting the temp, so I started doing that -- but it didn't seem to make any difference. This thing has me stressed out. 6/24/22 - After 6 months of working perfectly to keep my tank at 78 degrees, today suddenly the temp is at 79 and holding steady there. I hate this thing. Downgrading from 3 stars to 1.

Product works great. it runs a few degrees warm in my tank (set to 75, reading 78). Its been going strong for over a year now. It was a lot longer than expected, and I had to put it in at a slant on my 40 gallon breeder.