hygger Pinpoint Saltwater Aquarium Heater with Digital Thermostat IC Temp Controller, Titanium Tube Submersible Fish Tank Heater for Coral Reef 100 Watt

I really like the external power source and temperature setting and the unbreakable heater tube which heats slowly and dissipates slowly. And the user guide does say that the heater itself must be placed horizontally in the aquarium. A few days in, one of the suction cups came loose and it tilted to a 45 degree angle whereupon it started shorting out and messing with the power in the entire fish room. That was scary but it straightened up after I got it horizontal again. I've since placed a small flower pot underneath it to prevent that from happening again. But my biggest negative about it is the one degree spread before it calls for heat. In contrast the Eheim Jager heaters in my other two tanks only have about a 2/10 degree spread. All in all a good unit but not quite five star worthy.Update 5/16/2020: After a year in service, I've upped the rating to 5 stars. Had one eihiem burn out and one's stuck at 89 degrees and won't back off. This one however is working fine and that one degree spread is very livable.

Had to contact customer service before receiving unit. They were responsive, compassionate, and polite. Once the unit arrived, installation was easy, and the unit worked perfectly.

I just replaced another expensive digital heater in our tank that barely made it six months. This one was a much easier install as it is more versatile and I was able to insert the heating element unseen in the trickle filter below while adding the probe up top in the main tank. I mounted the control unit behind the tank and I can see the readout through the tank. So far so good and I will update this post as time goes on if this survives and performs as well as it is right now. I have had countless tanks, built many and also the filters. as I founded Aquarium Research many years ago and we designed the very first trickle filters out there. So, been around for awhile, I have lost count of how many crummy and so so heaters I have witnessed. This one looks quite promising.

"We don't suggest to use this temperature controller for other brand heater for security reasons."I have no idea what "security reasons" is supposed to mean, but for SAFETY reasons you SHOULD use a different heater, one with its own built-in thermostat, with this controller. If the temperature probe gets pulled out of the water (it happened to me, and I didn't notice until too late), or if this controller fails (other reviewers have had this problem, though not me), the heater will stay on and kill your fish.The controller uses a simple mechanical relay to turn the heater on & off, so you can use ANY heater (or combination of heaters) that does not exceed the power rating of the controller (500 Watts for the HG-902 controller, 200 watts for the HG-802 controller). Use a heater with a built-in thermostat, and set it slightly higher than you want to set this controller (but, not high enough to harm your fish). Then, if this controller fails and keeps the heater on, your fish will be protected.Also, the product description warns not to use this heater in an acrylic tank (presumably because the "titanium" heating element is unshielded and gets very hot). But you can use a shielded heater with this or, for more even heat distribution, TWO lower-power heaters (totaling no more than the controller's maximum rating) connected with an AC splitter. This is how I use mine, and it works great.So, you may ask, if you're going to use a heater with a built-in thermostat anyway, then why use this controller? Well, this controller is FAR easier to set accurately than those little twist controls on most aquarium heaters, it gives a large, easy-to-read display of your tank temperature, and it provides the backup protection described above.So, I really like this product, and only wish that the controller could be purchased without a heater since it is unsafe to use it with the "Titanium Tube" heater it is supplied with.By the way, if you're handy with electrical stuff, you could use even the HG-802 controller supplied with the inexpensive 50-, 100-, and 200 Watt models to switch a high-power external relay. Then, you could use ANY heater(s) you wanted, up to the maximum rating of your external relay. Kilowatts and kilowatts! I'm planning to do this with an 1600-gallon indoor pond that I'm currently constructing.Heck, you could even use two of these controllers connected in series (both probes in the water, first controller set for a slightly higher temperature) for extra safety. One controller might fail, but it's extremely unlikely that both would fail at the same time. Your fish will thank you by staying alive.

Keeps my water temp right on temp. Set at 90 for discus. 300W in 45gallon. The most I see the temp fluctuate is 1F and its very accurate to both a validated lab thermometer and an analogue thermometer. All 3 gave within 2F reading, right around that 90F mark. My tank has a glass cover which helps but so far this heater works well. I have the probe at the intake into my hidden built-in filer, which stages the heater, and flows back into the tank. So prob reads tank average output temp and accurately and quickly adjusts to maintain the temp. Wish I had used a heater like this before.

Stopped working at 4 months. Reads temp as 32F and thermostat says high but no heat is generated. Waste of $90. Don't do it!!!

Great product, fantastic and super responsive seller!! I have multiples of these and admittedly the 500 watt one did stop working BUT the seller responded to my emails at lightning speed and sent me a replacement immediately. I have owned a lot of aquarium heaters from a variety of brands (I have big turtles that like to break things) but I’ve never had such a helpful seller. Thanks mago!!!!Also more about the product, I LOVE the big bright LED temperature display hanging outside the tank. It allows me to quickly glance and see how things are reading throughout the day. It’s just designed really well and makes me life easier. I also like the shatterproof glass free design (WHY would anyone even make them with glass. So dangerous). There may be glass internally but nowhere it can harm my babies. And when it stopped working it just... stopped working. Nothing scary or explosive happened haha, I like previous heaters.