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Your cart is empty.4.4 out of 5 stars
Eheim Jager heaters are one of the only heaters available for aquariums that have a built-in calibration function, and most heaters are relatively accurate, but we have found that some can be off as far as 4 degrees. Even though the Eheim heaters were one of the best as far as temperature deviation, having the ability to calibrate them makes them even better. Calibrating the heaters can be done either in your tank while they are running, but we highly suggest calibrating them in a 5-gallon bucket since it is a much smaller volume of water that can be heated or cooled much quicker, the only other thing you will need is a reliable thermometer or temperature probe. Once the heater has heated up the water to the indicated setting, you can use the thermometer or probe to read the temperature of the water, and if it does not match the heaters setting, then you will want to turn the red indicating arrow until it matches the same temperature of the water. That will allow you to accurately adjust the temperature of your aquarium without having to compensate for any deviation that the heater may have.
Eric V
Reviewed in Canada on November 26, 2022
I have 7 eheim jager heaters running at the moment on 7 different tanks, and they all keep the temperature steady. It may not be accurate to the dial setting, but that doesn't bother me. What's more important is reliability and consistent temperatures. Eheim is one of the oldest and most reliable aquarium product brands for good reason.
Customer
Reviewed in Canada on March 30, 2021
Using this to heat a 5gallon planted aquarium to about 79degrees and it does the job really well. The only downside is that it is a little big in size but other than that I’m happy with the purchase.Didn’t need calibration and holds tank temperature steady. Very easy to setup and use. Solid build quality from the glass to the wire.
Kevin W.
Reviewed in Canada on August 2, 2017
Always buy quality tank heater so you don't fry your aquarium pets alive, great quality, brings temp to desired level. Make sure you follow instructions. Worked well for my 5gal. Tank. It is a little bigger than other ones but definitely worth the purchase
Customer
Reviewed in India on July 24, 2017
VERY VERY GOOD PRODUCT
Artosaurus Rex
Reviewed in the United States on March 2, 2016
Besides being a little hard to set the temperature, which there are videos of how to do it on youtube, it holds the temperature perfectly. I have a 5.5 gallon tank in my room that is sometimes in the low 60s°F over night. I keep my tank at 80°F. I've never had a single problem with this thermostat. I never even see the tank temperature off by 1°F.Yes, its a little large, for its wattage, and also for my tank size, so I have it installed on an angle. Its probably large for a reason though, so I am fine with that.The suction cups aren't the greatest, they still hold but after weekly cleanings for the past year, where I do take the thermostat out, the suction cups are getting weak. You can buy replacements or lay the heater on the floor since it is completely submersible. I am planning on replacing the suction cups with magnets anyway, but sometime when I have more time to play, but I do think the suction cups will hold until I am ready, and that may be awhile. The power cord is great, it is long, has a great feel, and I don't think I will ever have a problem with it.The main reason I chose this was one review I read. Their tank leaked while they were out, losing all of the water (poor fishes), and this heater suffered no harm from that.The price is great too, for such a quality product, its priced the same as the junk ones in the chain pet stores. That one couldn't even keep the temperature consistent, let alone heat up the tank to the temperature I wanted. It was also a 50 watt heater like this one too. This one doesn't spend a lot of time on unless I just changed the tank water and its bringing everything up to temperature.If all Eheim products are like this, I would use all of them.
Alan Folley
Reviewed in the United Kingdom on June 3, 2015
fantastic product always hi quality and reliability from Eheim, an excellent product for small aquariums, top marks
Georgia
Reviewed in the United States on January 1, 2015
i have owned this heater for 5 months and overall i am very pleased. i read probably every review on here for it before buying but theres some things i found that i haven't seen mentioned. i planned on laying the heater horizontal on the bottom of the tank but in the directions it says it "HAS" to be vertical and when i emailed the company asking questions about it they didn't respond. i also didn't realize exactly how long this heater is, the 125watt is 12 inches long. it doesn't fit in my 10 gallon tank vertical so i was going to lay it horizontal on the bottom like i originally planned but then i found out it. floats. so i ended up using the suction cups to have it be diagonal on the side of the tank. but on the plus side its extremely accurate. i check the temp several times per day and its always exactly 80 degrees (where i have it set) and i hardly ever see it kick on. so if you have a small tank and need a large watt i would probably recommend a different heater, otherwise this heater is amazing. i think on the eheim website it lists how long each watt is, so do your research.update - aug 2015the heater still works great. i still have it suction cupped diagonally. i did have to recalibrate it once the weather warmed up but i'm pretty sure i didn't do it right. i wanted to lower the temp to 78 and it wouldn't lower so thats when i recalibrated it and i still can't get it to 78 degrees. it stays at a perfect 80 degrees. which isn't a huge deal. i think the weather is just too warm to get it to go below 80. but the fish seem to prefer 80 degrees anyways. something i'm disappointed about is it was hard for me to find instructions on how to recalibrate it, and because of that i think thats why i did it wrong. overall i still think its a good heater. if money is an issue though, there are other heaters that are cheaper and do just as good. but there aren't a ton of other heaters that come in a 125w. most of them are either 100w or 150w, so its definitely a plus that thi one comes in a 125 because for me 100 isn't enough and 150 would probably be too much. i've seen in other reviews people say the suction cups wear out, but i've owned this heater for a year now and it hasn't happened. i don't really know what i'll do if the suction cups give out. i don't know if replacements can be ordered. if they can, at that point, figuring in shipping and stuff it might be more cost effect/the same price to just buy a different heater. i don't really know.
Rodney A. Figueroa
Reviewed in the United States on May 2, 2014
I've owned 3 of these particular brand of heaters in the past few years and they're still in service.Pros: It's a glass heater with the kind of pedigree that shows it's reasonably good quality. The glass is thick and the heating element well constructed. The dial is firm and holds the set temperature when you figure out how that works, and the heater is very powerful. They seem to be rated at lower wattage but heat more water than competitor heaters. The indicator light is bright and the cable is thick and well attached to the top housing.Cons: The heater is still a glass heater, Eheim Jagers aren't known for exploding, but as with any glass heater, there's always a risk of thermal shock and catastrophic failure. I have never experienced it in these heaters so perhaps that's something to be said. The temperature dial is a pain in the ass to properly set. You have to use the enclosed instructions to understand how to properly calibrate the heater and even then, small deviations in the dial as it's turning might lead to slightly too cold, or slightly too hot water. Long term tests of the seals for these heaters show that they do leak after a time, in a marine application. The salt water just damages the seal on the top of the heater and eventually causes it to fail. Best practices would encourage the user to not fully submerge this heater up to the sealed moving parts at the top, but keep it around where the minimum water line requires.Overall, I've used these heaters before, and if you're on a budget and need a high quality heater, this is definitely worth giving a look.
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