hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving Water Automatically Stop Heating System, for Freshwater and Saltwater

I bought this version to go in with my eels because it showed the tiny holes instead of the long slits. Well, it has the big slots down the side that a baby eel can get into. It works great, just had to put one side against the glass and a tall anchor against the other long opening. The cage design is the only thing, please make one for baby fish or eels growing up in my 75 gallon. These heaters have been my favorite. They have safety measures in case something goes out. The thermostat and the error message saved my fish. Display is a lot nicer on this newer model, the adhesive hook sucks butt, lasted maybe a day. Just grab a command hook that'll fit and use that, it won't move, like ever. Design is very nice, we just need one for the babies that like deep dark crevices. Love your products, please switch out that barely dollar store adhesive hook, your product is waaaay to good for that to represent your brand. See if command hooks will collaborate. I usually try to buy only hygger now for my aquariums. I've had one heater knocked around by my black banded leporinus and it broke after about 3 years. I've had the same one going in my indoor koi pond for 4 years, my predator tank has had one for 4 years and my tiny 15g grow out/ hospital tank for 3 years. My 20L breeder only had issues because I drained it and forgot to unplug the heater (tight space, my forgetfulness). It was still working after cooking without water, but replaced it just in case. If you like Hygger, their wave makers are awesome! Really nice attachment with heavy duty magnets. Chefs kiss. All the poopoo makes it to the intake. Both sides are currently sitting at 78. The heater is literally plug and play. I generally at least rinse ending going into the tank, stick it to the side, plugged it in, adjusted the temp and ready to go. I did use the hook on a clean flat wall.... it fell sometime in the middle of the night. Super easy to use, heat seems to be spot on. 10/10 (we're not judging the free included dollar store hook).

Super easy to use, got a year out of it before the temp sensor started acting up and the tank was reading way hotter than it actually was but controller did its job by shutting the power off to it and sounding the little alarm. For the price point I won’t complain with getting a year worth of use out of it.

The heater works great. The only problem is, that the suction cups don't hold very good. The heater is heavy so it contantly slides down. We don't hang ours like some people, we have a bigger tank and put it sideways. Then it slips down onto the rocks.I wrote the company and they want me to pay $10 shipping for 4 suction cups. They don't sell the suction cups online in amazon or any other store. I guess they don't realize that the rubber softens overtime and need to be replaced.

Update 03/29/2025: Hygger as a company was very responsive, and sent a replacement heater to me within a week. I installed it in my 55 gallon, having replace the 125gal heater with a more trusted brand. This morning I found my 55gal tank with 2 adult angels and a handful of fry sitting at room temperature. The Hygger heated indicated it was "heating" but displayed 0 watts being used by the heater. The tank was 67 degrees F when its supposed to be at 82 F. I will no longwr trust this hygger heater and will not be using it in the future. This is the second hygger heater that has epxerienced a fault in roughly 6 months of use. Original: It has been a very effective heater up until this point. It now has an intermittently auto shut off alarm, claiming that the heater is outside of the water. It turns itself on and off constantly with alarms switching between out of the water and normal. So it's auto shut off feature does in fact shut the heater off, but obviously faulty because it's shutting itself off while fully submerged. I don't think I will continue entrusting my 125gal to a faulty heater.

This heater is amazing! I use it in a 150 gallon stock tank where I'm raising 20 tilapia. The water in this tank is way warmer than the tanks without a heater. It's easy to use, and seems to be pretty durable. I will be purchasing this again!

It works like any aquarium heater but is way more powerful as it is a 1kW heater (for an outdoor pond). What I like is the readout that says the temperature, easy 1 button setup, readout shows wattage, auto-shutoff if taken out of the water, and the heater adjusts output based on surrounding temp. Cons - the casing for readout is flimsy, not sure how long it will last before I start getting error readings and have a useless heater, wish it was bigger (had more surface area). UPDATE: after a few months of use I have encountered some issues. The casing enwraps the tubes too much so that heats build up quickly inside and the device reached set temp quickly. It then shuts off. Also as the device gets close to the desired temp it reduces the wattage output. All this would be great in an enclosed, housed inside, aquarium but does not bode well for a pond that has a large surface area. They need to keep the thermostat away from the heating tubes so the device has a better idea of the surrounding water temp. There is another hygger that has a more open casing and that one allows for more water to heating tube exposure. The temp controller had to be placed in another casing to prevent moisture/water damage. Shouldn't have to do this for a device that will be around water. Bought the competitor Aqqa (1200w) and it pretty much the same thing with similar issues (thermostat errors). Someone need to ek a heating device where the thermostat is on a cable nearby but away from the heating unit.

(Update) Company reached out to me to provide me with either a refund or a replacement for the failed heater. I do appreciate such effort to stand by their products. I will continue to purchase from hygger even after this one minor issue. I purchased this heater in March of this year, was working very well and I was very pleased with the product until it died over the weekend. No issues; just stopped working. I did everything to trouble shoot. It simply wont heat. Not worth the price if its only going to work for six months.

Working well for our fish tank (500 gal stock tank) for goldfish. Easy install and use. Heater cycles on and off to keep temp consistent

Excellent produit. Fonctionne parfaitement. Chauffe rapidement. Je l’utilise dans un aquarium 90 gallons et il maintient parfaitement la température. Affichage facile à lire. Facile à utiliser et à ajuster. Identique à la description et aux photos. Vraiment très satisfait!

Heater overheated overnight and killed all discus that I had in a 120 Gallon tank. The heather was just over a month old therefore could not return to Amazon. Hygger had agreed to refund me however since the agreement they are ignoring me. This unit was on a 12 month warranty (less than a month in thank). I have two more of there heaters that I will return to Amazon. Please read other comments posted on Amazon regarding these units before you buy.