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

Heater was delivered the day after I ordered it as expected. It comes well packaged and even has a plastic ring around the bottom of the tube to protect it in transit. I would have liked it if the cord was a bit longer. If you have your electrics hidden in a cabinet like I do, you need the cord to be able to go down the back of the tank, down the back of the cabinet and then into cabinet to where the extension socket is. If you don't have your aquarium right next to a socket, you are going to need an extension.Some people wonder why this heater 'needs' to be calibrated. I think that the truth is you don't really need to calibrate it, you could just set it to a reasonable temperature depending on your stock and then check the temperature with a thermometer for the first 24 hours or so, adjusting up or down as necessary. I think that the reason for the calibration wheel is that it enables you to set the exact temperature (in half degree increments) regardless of the ORIENTATION of the heater. Most people will hang their heater diagonally, the instructions for this one say to place it vertically but I have heard of people placing it horizontally as well (to hide it behind plants for instance). You can imagine that depending on orientation, the the thermostat might read the ambient water temperature slightly differently.The other thing that I like about this heater is that it seems to be a bit more efficient than others I've looked at. I used the 100w model to replace a 150w Fluval model that exploded as I removed it from the aquarium (never do a water change without turning off your heater first!) Looking at other models of heater, a 150w model was suggested for my 129 litre tank. In this range, the Jager 100w seems to be enough. Not sure how this is possible, but it seems to work fine. Perhaps the heater is cycling less and that can only be a good thing in terms of the stability of the water temperature and the longevity of the heater.

After a few time-consuming and tedious back-and-forths with heating, this is consistent and accurate keeps the temperature at the specified mark, is slim and discreet and never looked back after getting it. Not sure about the thickness as it has not broken but it is comfortable and safe to touch as a working heater should be. Would recommend.

So far so good.I had to calibrate slightly (which is easy to do). The eheim heater is now heating my aquarium to a nice steady 26°C which I am very pleased about.I previously owned a Deltatherm Aquarium Heater which suffered from internal condensation and would make loud clicking noises during and after heating, it also had a fluctuation of about 2°C, so within a 3 hour window it would go from 26°C to a reading of 24°C then back to 26°C

I set it to 27 degrees and when I checked it with another thermometer it was 32. It needs calibrating.

Once the temperature dial was properly calibrated, for which instructions are provided, I have to say this heater keeps our 100 litre tank with an external filter within 0.2 of a degree from target. It’s well made, of good quality and so far has been absolutely perfect.

Works a treat and so far is keeping my aquarium at a constant temperature within about +/- 0.5degrees C. The setting on the thermostat also agrees with the reading on the tank thermometer. No idea of running costs yet, haven't had a bill!

Only just got and installed, but this product is fantastic.Placed in tank easily, and it stays in place.The temperature has been set and it is accurate out of the box.(Verified with digital thermometer)

Unfortunately it didn't hold its heat, no matter what I did with it. Returned and bought a Fluval heater and it works a charm :)