B07H31LG15 US
hygger Marine 50W Titanium Aquarium Heater for Salt Water and Fresh Water, Digital Submersible Heater with External IC Thermostat Controller and Thermometer, Fish Tank Heater for Fish Tank 5-10 Gallon 5 Most buy military*** This this is amazing and is worth the money. I have a 10gallon tank that was at 72 degrees. This heater warmed it right up and now my Betta and guppies are more active. I would definitely recommend this product. B07KBXF5XD US
Kinbo Aquarium Heater 300 Watt Submersible Fish Tank Heater Adjustable Temperature with Diving Thermometer and Protective Case Suction Cup 1 3 months accessory :( Sally H*** Bought it October 2 and it did not make it to new year. One star because zero isn’t an option B083TNTFMK US
DaToo Aquarium Heater Fish Tank Heater Submersible 25 Watt, 1 Yr Warranty 5 Nice little heater! Nanette*** Nice and accurate heater. Use it in my 9 gal. Fluvial Flex shrimp tank. Keeps a great steady temperature. The added thermometer was a great plus. I recommend this product. B08B3HWTY9 US
HITOP 25W Adjustable Aquarium Heater, Submersible Fish Tank Heater Thermostat with Suction Cups for 5-10Gal 5 Great Madison*** Great B09C1BZGSB US
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic 3 ??? wlj*** When I turn the aquarium light off the heater goes off too. Otherwise works great B09DK9K87Q US
YOFOTHS Adjustable Mini Aquarium Heater 0.5/1/2/3 Gallon Submersible Small Fish Tank Heater 10W/2... 1 Does not work Joh*** Tried to recalibrate it following the instructions given, still would think it was out of water, tried multiple depths and got shocked, never again..... B09H2SF5XM US
YukiHalu Small Submersible Aquarium Heater, Adjustable Mini Fish Tank Heater 25W 50W 100W 200W 30... 1 Cooked my fish! Shirlg*** I had 2 of these and the one in my small guppy tank suddenly just went haywire and cooked all of my guppies, fry too! I have another in my beta tank that I will also be returning before it happens to him... B09H4JBC3H US
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic 5 My Red Eared turtles love it!! BAd*** Heater is perfect size, consistent, and easy to adjust. I have a camera in my greenhouse for them and I can rotate the camera to check temperature set and actual temperature. B09LM8S7WS US
YukiHalu USB Powered Aquarium Heater, 10W Adjustable Mini Fish Tank Heater with External Temperature Controller, LED Display, 1 Can't even keep my 1gal tank above 72°F Kaylee *** I got this for my tank since I have it by a window and live in a cold state, it does absolutely nothing and my poor fish is probably so cold. Waste of money. B0BC6HLMY1 US
Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater & 5 Works Amazon C*** Use it to warm up my 5g bucket of feedwater. Does what I purchased it for B0BCJ1369M US
HiTauing Aquarium Heater, 200W Fish Tank Heater with LED Digital Display & 5 Safety Protection, Submersible Aquarium Heater w 5 works great Pat*** it's so nice to have a digital readout of the set point and the actual temperature B0BCP6GPCT US
Aquarium Heater 300W Upgraded Fish Tank Heater With Leaving Water Automatically Stop Heating And ... 5 Great Aquarium Heater! Big*** This Heater is better than described. I have had it for a week put it on 78 and it has been reading 77-78. I have another temperature gauge and it reads the same. This one sales for three times less than the one I replaced. You cant go wrong with this Heater. B0BF3S1LWH US
hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving 2 Didn't even last a year! Venice*** I bought this heater in August 2024, and it stopped working May 2025. Didn't even last a year. It started beeping loudly and giving me the error message "EE". I guess what it's telling me is that the two sensors in the heater are detecting 5° difference. Well damn, the water temp shouldn't be different from one side to the other. There's no way to calibrate them so I guess I'm s@#$ out of luck. Kind of upset! B0BF3Y6PZM US
hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving 5 Hygger 800w heater d f fc f2*** Was a great heater while it was working didn’t make it 3 months B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 Quality aquarium heater and controller. T*** This is a really nice aquarium heater. It is well made and durable enough for my needs. The metal heating tube feels solid and stronger than glass tubes. The heater was really easy to set up and use. The controller shows the current water temperature and set temperature. It can be displayed in both celsius and fahrenheit. The temperature is really easy to set the the buttons on the controller. I have been using the heater in the sump of one of my aquariums, and it has been working very well. The heating tube isn't too big, which makes placement easy. I was able to hang the controller on the cabinet next to the sump which makes it easy to monitor the temps. It has been very accurate so far when testing it with other thermometers. Overall, I am very happy with it. It is a good value for a quality aquarium heater and controller. B0CQ28NCLC US
hygger Aquarium Heater 300W 500W 800W 1000W 1200W, Large Adjustable Fish Tank Heater with Intelligent Automatic Power-Off System, Water Heater with LED Digital Display, for Saltwater and Freshwater 5 Quality Kar*** Great product with quality showing in their Manufacturing process. B0DFXQ7SJM US
hygger Aquarium Heater 500W Fish Tank Heater with LED Controller, Multiple Safety Protections, Anti-Cooking Fish Alarm, Auto Stop Heating Protection, for 66-135 Gallon Freshwater Saltwater Tank 5 Good product for the price John W*** Works great as it should 👍🏻 B0DK4ZZ6K9 US
DONGKER Small Aquarium Heater,5W/10W/15W Mini Fish Tank Heater Constant Temperature 78℉(26℃) with Overheating Protection for 1-2 Gal Tanks 2 Not 15W Orph*** I was not able to get the 15W heater I purchased to go above 11.6W. I gave it two different 5V 5A chargers. One gave 10.8 and the other 11.6. I like the size and that it's USB low voltage. The temperature in a test container of 32oz went from 63 to 77 in about 17 mins. B0FDGMZYDV US
Titanium Aquarium Heater 200W, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 20 ~ 40 Gal Saltwater Freshwater Fish Tank, MX-9016(200W) 5 Good product Jim M. *** Works as described. B0FN7DXHFR US
UPETTOOLS Submersible Aquarium Heater with Digital Thermostat, Adjustable Temperature Fish Tank Heater with Overheat Protection, for Small Freshwater Tanks 5 Functional water heater for small tanks QuickDr*** This water heater works fine for my 5 gallon betta fish tank. The heater is thin and small which makes it fit in your tank easily. The light displaying the temperature is easy to read inside the tank but this might be a drawback as typically you want to hide your water heater. Suction cups stuck well to the side of the tank and have had no issues with the heater falling off. The heater has been tested for accuracy and found to be off by no more than half a degree Fahrenheit which is by my standards acceptable. The heater is slow to heat up even a 5 gallon tank which is good in one way because it doesn’t shock the fish but also a negative if you need to get the tank to certain parameters quickly. Overall packaged well, nice looking modern fish tank heater. B0FX2B23J5 US
HiTauing Aquarium Heater 25W/50W/100W/200W/300W, Adjustable Knob Fish Tank Heater with Digital Thermometer, Submersible Betta 5 Quality Rod Dic*** Nice! Thanks B09C1BZGSB US
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic 2 Good for newbies, but doesn't last Dam*** Purchased this last year for my fish tank. About a week ago it malfunctioned late in night with the "HH" error. I went online to see if there was a way to fix it and tried several different options none of which worked. A good affordable option for starting out, but prioritize getting a replacement/backup so your fish are not left in the cold. B09H4JBC3H US
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic 2 Quit working Amazon C*** Item quit working in less than 2 years. Can't go above 64 temp. Set to 82 and no longer will heat to that. B0BC6HLMY1 US
Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater & 1 Worked while it lasted Amazon C*** Have been using this product for under 3 weeks now and I saw this in the tank today. The part completely melted off?? I don’t know how that happened B0BF3Y6PZM US
hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving 1 Doesn’t work -POS crap Matth*** Don’t buy this brand B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 4 Fast Heating Substantial Aquarium Heater T*** This 500W aquarium heater is very simple and easy to set up. One button toggles the displayed temperature in C or F measurements, and a long press of “set” button enables setting the target temperature. The unit includes a thick, three-prong power cord that stretches approximately 62 inches. The thick cord that connects the heater to the control box is also ~ 5FT. I tested the effectiveness of this heater using a 5 gallon bucket of cool tap water. For the test, temperatures were measured using a submersed digital aquarium thermometer and a floating mercury thermometer to verify. The starting temperature of the water was 69.8F (fahrenheit). Upon setting the target temperature at 79F, the 5 gallons of water reached the target temperature, according to the heater’s thermometer, in about 10 minutes. However, the heater’s temperature readings never aligned with that of the two comparative thermometers, which differed ~4 degrees at the stabilized reading. Furthermore, since the heater interpreted that the target temperature was reached, the water remained at a consistent 74 degrees, according to the other thermometers, and did not continue to heat the water further. The heater didn’t evenly heat the water, as water at the bottom of the bucket was noticeably cooler than the middle or closer to the surface. The product instructions do emphasize that this heater “needs to be used in conjunction with a submersible pump or water circulation system to obtain a more accurate temperature”. Likewise, when I manually circulated the water, the displayed temperature dropped and the heater shifted to “heating mode” again. Although not perfect, the test demonstrated that the product does quickly heat water. As a precaution, I’d recommend using a separate thermometer on the opposite side of the aquarium for comparison to verify even distribution of heated water. Furthermore, it is important to create adequate water circulation to facilitate heat distribution and more accurate temperature readings, as also noted in the product instructions. I have not rated "perfect" since I couldn't confirm displayed temperature accuracy or achieve alignment with readings of the comparative two thermometers (both of which displayed the same temperature). While I have not used this aquarium heater in a large/65-95 gallon aquarium, the device feels solidly constructed, substantial and sufficient enough to get the job done. B0DFXQ7SJM US
hygger Aquarium Heater 500W Fish Tank Heater with LED Controller, Multiple Safety Protections, Anti-Cooking Fish Alarm, Auto Stop Heating Protection, for 66-135 Gallon Freshwater Saltwater Tank 4 inaccurate temperature readings Indofros*** doesnt seam to be able to hold temp very well and is off by +/- 5 degrees B0BC6HLMY1 US
Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater & 5 Mi opinión Luis José To*** Buen producto B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 Titanium Instead of Glass or Cage… Simple & Sleek. Sud*** I go through aquarium heaters rather regularly… I have extremely hard water and the heaters tend to get scaled up. In fact, my last heater had a plastic cage to protect it, but developed a huge mound of scale within the cage. This heater is smooth and sleek with its titanium cover that won’t crack. I like that I’ll be able to see any calcium buildup right away so I can remove it with a vinegar bath. I do like this style of heater with the temperature control as I don’t have to rely on an aquarium thermometer. However, I do have one to fine tune any differences between the heater and the temperature I want. The sleek design makes it easier to put in the aquarium without having to remove the lid and the suction cups held well. I did place it under one of my filter outputs as recommended for optimum heating of the aquarium. As always, I let the heater sit in the aquarium for quite a while to calibrate before plugging it in. B0DFXQ7SJM US
hygger Aquarium Heater 500W Fish Tank Heater with LED Controller, Multiple Safety Protections, Anti-Cooking Fish Alarm, Auto Stop Heating Protection, for 66-135 Gallon Freshwater Saltwater Tank 1 THERMOMETER IS IN THE HEATER IM*** Buyer beware: this system does not include a temperature probe; the sensor is INSIDE the heating unit. Think about that. Maybe this works just fine for heating a bucket or a reeeeeally small tank, but I bought this for my 125 gallon turtle tank and it's been 24 hours of alarms, because the damned thing thinks the water is 95 degrees. (Spoiler: I pulled out some actual thermometers, and it's 74.6 all over) as soon as it shuts the heater off, the "temperature" drops rapidly (duh) and, since it turns the heat back on when the heater reaches 79 degrees, we start the cycle all over again. I'm so disappointed in Hygger. I did look at their other systems and found one or two with separate temperature probes, but at this point I'm just going to go back to the (slightly more expensive) heater that served me so well for over 5 years. This one will be returned as soon as the new one arrives (winter, 74 is better than 65) I bought a 300W for my other tank; thank goodness I decided to try out the 500W on the less sensitive tank first! B0BC6HLMY1 US
Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater & 1 Blew up and caught fire when turned on. T. Ma*** Within 5 seconds of turning this on for the first time after placing it in the tank, the unit essentially exploded, started sparking and smoking, then melted the side of my brand new tank. Pretty terrifying to think this was going to be placed in my son’s room. B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 Solid build, easy to use Jame*** The heater itself feels really solid with the all-metal build. The power cable is thick like you would hope for something of this voltage, and is a nice length for a heater designed for big aquariums. The temp display is nice and bright, adjustment is easy, and it comes with a neat attachment to mount the heat adjustment/display box to a wall or tank stand. It heated up fast and seems to stay pretty consistent. B0DFXQ7SJM US
hygger Aquarium Heater 500W Fish Tank Heater with LED Controller, Multiple Safety Protections, Anti-Cooking Fish Alarm, Auto Stop Heating Protection, for 66-135 Gallon Freshwater Saltwater Tank 5 Get ready for tropical temps on demand Mike M*** The is perfectly sized for my 75 gal aquarium and also has optimal temperature control ranges B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 Works great for my 65gal tank Ro*** I ordered this for my 65gal turtle tank. I have a red eared slider and his water temp is meant to be between 75 and 80 degrees. My previous heater had recently gone out and the water was dipping lower than it should, so I was ecstatic when I came across this. The package arrive in perfect condition and the heater is easy to use. The instructions are simple and I had no problem setting the temperature to what I need. The heater part that goes into the tank is metal and sturdy with suction cups that work extremely well. I was positioning the wand in the tank and one of the cups latched onto the wall and did not want to come back off. In other words, I'm very confident that this will stay secure and in place. The heater worked great to level out my water temp quickly and within in hour it was in the correct range. There is no barrier for this, so I set the wand near the large rocks to avoid my turtle reaching it and accidently burning himself. The price for this is high, as with all heaters of good quality, so it's definitely worth the cost. Overall this is a great buy and I absolutely recommend! B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 Heat Of The Moment Vine Reviewer*** This Weipro 500W titanium aquarium heater is aimed at larger tanks, and the titanium body is the big appeal. I like titanium heaters in saltwater because there is no glass tube to crack, and they generally make more sense around rockwork, sumps, and bigger systems. The digital controller is easy to read, and the adjustable temperature range gives it flexibility. Pros: Titanium construction, external digital controller, strong 500W output, and a clear display. It is a better style of heater for saltwater use than cheap glass heaters. Cons: I would still use this with a separate temperature controller or aquarium controller on any serious reef tank. Heater thermostats are one of those things I do not fully trust by themselves. Final thoughts: A capable heater for larger aquariums, especially saltwater systems. Good hardware, but still worth backing up with an independent controller for livestock safety. B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 High quality, efficient heater, easy to use easy to read very versatile Stunt*** First of all, I’d like the durability of the actual heater that goes in the water. It’s not glass so I don’t have to worry about it shattering in the fish tank. I also like the large display that sits outside the fish tank. It allows you to set a certain temperature and it always hits that temperature if it gets cold it turns on to maintain the temperature if it gets too hot it goes off so it cools down and maintain that temperature. It’s also very easy to read. This is a high-quality heater. That is a great addition to my many tanks. It seems a good quality and durability so it should last a long time. The set up was very easy and simplistic. It easily stuck to the side of my tank with the additional sticking media that was provided. B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 Great quality, large module Don*** This is a hefty aquarium heater! The module is pretty large, so be aware of your available space options for a spot to put it. It does have a significantly lengthy cord, both to the module as well as module to heater, so it does leave a lot of possibilities on placements. The screen and numbers on the module are bright, and large, so its easy to see from a distance if theres any questions on it. Not having glass around the heating element is a bit unnerving but I do appreciate that theres no glass to break or anything that could Crack. The instructions do say it must be fully submerged, as expected, but it can be horizontal or vertical, so it definitely increases the options there as well. Makr sure to get the appropriate heater for your size tank. It is a well made piece of equipment and I think will work great for my tank! B0CL6KGYLP US
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W) 5 For anyone looking for a reliable heater with a clean setup and straightforward controls! Mart*** Weipro is slowly taking over my tank, and honestly I’m not mad about it. I like that Weipro keeps the pricing fair for the quality you’re getting, and while it might not look flashy, this feels more premium than a lot of other heaters in the same range. This 500W titanium heater feels like a solid, well-built piece of equipment and it does a great job of keeping things at a steady temperature without feeling overcomplicated. Installation was super easy since it's so compact, and once I had it in place it was simple to set the temperature and get everything running the way I wanted. The only real flaw I could find is that the display screen has a frosted plastic effect to it, which makes the LED readout a little tricky to see at a glance. I also wish it had a protective guard around the heating element, just to help keep heat-loving fish from getting too close to it, although I can understand how leaving that off helps keep costs down. Even with that, it’s still a very strong heater overall and has been doing exactly what I needed it to do. For anyone looking for a reliable heater with a clean setup and straightforward controls, this is a very good option. B000IWXHMI US
TetraFauna Aquatic Reptile Heater 5 Fixed Heat setting is so good for the turtles. Ken *** I have two rescued painted turtles here in Ohio. I keep them in a 55 gallon tank. When the vertical fish tank heater died out they became sluggish and of course lost their appetite. I keep about 30 gallons of water in the tank and this heater (on the lower right side by the filters with water movement) keeps this set up constant at 76-78 degrees F. I love the hard protective shell around it and the quick and easy stick down and plug in set up. They love it also sleeping near it every night. Great product and arrived guickly, we are satisfied happy campers indeed. B07BT5FT13 US
DaToo Aquarium Heater Fish Tank Heater Submersible 100 Watt, 1 Yr Warranty 1 Crappy product sama*** This item is worthless cracked well inside tank then busted inside tank while tank was still full of water B07WFSZ13K US
MQ Submersible Aquarium Heater Auto Thermostat, 200W Fish Tank Heater with LCD Digital Aquarium T... 5 great heater Herman *** Works great not much different in real temp maybe a couple degrees B07ZWX5QMN US
Fish Tank Heater 1 Fish tank heater Julian*** It did not work!! Brand new and I. had to send it back and it was a pain to return it and get my refund. B0917RY834 US
Submersible Aquarium Heater, 800W/1200W fish tank heater, double tube heating, rapid heating and energy saving, LED digital temperature controller, suitable for sea water and fresh water(1200W) 2 Worked great when it worked (No Reviewer*** It kept my koi warm during the winter a few years ago. Went to put it in the next and it just shows ee. Useless B09C1GH8PQ US
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic 5 Heats my 10g and has adjustable temp Eric B*** Good range of temperatures. Was able to set to 90F to germinate seeds and back down to a temperature to keep shrimp in my 10 gallon tank B09H2SF5XM US
YukiHalu Small Submersible Aquarium Heater, Adjustable Mini Fish Tank Heater 25W 50W 100W 200W 30... 5 Amazing Product James *** I was looking for a good heater for my 2.5 gallon aquarium and I came across this heater. I bought the 25W heater and I LOVE it. The temp is very easy to set with the digital display and it keep the temp at what its set to. Very good product! B09H4JBC3H US
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic 1 Fire risk Sele*** As I was doing a 20% water change on my tank I noticed smoke coming from the back of the tank. The unit started melting the plastic and smoke everywhere. Thank God this happened while I was at home in front of me or it could have been a different outcome. Very scary, I thought this device had a safety feature to prevent over heating....😫 B0B55X425X US
AquaMiracle Mini Aquarium Heater 5V/2A USB 10W Small Fish Tank Heater for Tanks up to 1 Gal, Digital Display Thermostat Betta 5 Small but mighty Ani*** Perfect for my three gallon. Not big or bulky and looks good in tank. Sometimes i do have to push the temp up a little but definitely peace of mind knowing it won’t overheat. Batman approves 🐟 Bottle is for size reference B0B5XJXL8W US
AquaMiracle Aquarium Heater 100W Fish Tank Heater for 10-20 Gal Tanks, LED Digital Display Thermostat Turtle Heater with Out-of-Water Auto Shut-Off, Overheat Protection & Memory Function 1 Piece of junk meriam *** Quit on me less than 2 months. Never buying again B0BC6HLMY1 US
Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater & 5 Great fixed temp heater Kelly and*** Love it, works great for my african drawf frogs, a perfect 78 degrees. B0BF3S1LWH US
hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving 3 Not reliable heater, company does not respond when requesting support NANCI A*** Heater emits a beeping noise on occasion. Information about this is not included in the manual. Have sent two requests to company about this with no response. Heater does not always heat even though I position it in tank per manual instructions. Would not recommend. 
hygger Marine 50W Titanium Aquarium Heater for Salt Water and Fresh Water, Digital Submersible Heater with External IC Thermostat Controller and Thermometer, Fish Tank Heater for Fish Tank 5-10 Gallon
Kinbo Aquarium Heater 300 Watt Submersible Fish Tank Heater Adjustable Temperature with Diving Thermometer and Protective Case Suction Cup
DaToo Aquarium Heater Fish Tank Heater Submersible 25 Watt, 1 Yr Warranty
HITOP 25W Adjustable Aquarium Heater, Submersible Fish Tank Heater Thermostat with Suction Cups for 5-10Gal
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic
YOFOTHS Adjustable Mini Aquarium Heater 0.5/1/2/3 Gallon Submersible Small Fish Tank Heater 10W/2...
YukiHalu Small Submersible Aquarium Heater, Adjustable Mini Fish Tank Heater 25W 50W 100W 200W 30...
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic
YukiHalu USB Powered Aquarium Heater, 10W Adjustable Mini Fish Tank Heater with External Temperature Controller, LED Display,
Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater &
HiTauing Aquarium Heater, 200W Fish Tank Heater with LED Digital Display & 5 Safety Protection, Submersible Aquarium Heater w
Aquarium Heater 300W Upgraded Fish Tank Heater With Leaving Water Automatically Stop Heating And ...
hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving
hygger Aquarium Heater 300W/500W/800W/1000W, Submersible Fish Tank Heater with Digital LED Controller and Intelligent Leaving
500W Titanium Aquarium Heater, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 65~95 Gal Saltwater Reef Fish Tank, MX-9016(500W)
hygger Aquarium Heater 300W 500W 800W 1000W 1200W, Large Adjustable Fish Tank Heater with Intelligent Automatic Power-Off System, Water Heater with LED Digital Display, for Saltwater and Freshwater
hygger Aquarium Heater 500W Fish Tank Heater with LED Controller, Multiple Safety Protections, Anti-Cooking Fish Alarm, Auto Stop Heating Protection, for 66-135 Gallon Freshwater Saltwater Tank
DONGKER Small Aquarium Heater,5W/10W/15W Mini Fish Tank Heater Constant Temperature 78℉(26℃) with Overheating Protection for 1-2 Gal Tanks
Titanium Aquarium Heater 200W, Submersible Fish Tank Heater with Digital Display Temperature Controller, 0℃-40℃ Adjustable, Fast Heating for 20 ~ 40 Gal Saltwater Freshwater Fish Tank, MX-9016(200W)
UPETTOOLS Submersible Aquarium Heater with Digital Thermostat, Adjustable Temperature Fish Tank Heater with Overheat Protection, for Small Freshwater Tanks
HiTauing Aquarium Heater 25W/50W/100W/200W/300W, Adjustable Knob Fish Tank Heater with Digital Thermometer, Submersible Betta
TetraFauna Aquatic Reptile Heater
DaToo Aquarium Heater Fish Tank Heater Submersible 100 Watt, 1 Yr Warranty
MQ Submersible Aquarium Heater Auto Thermostat, 200W Fish Tank Heater with LCD Digital Aquarium T...
Fish Tank Heater
Submersible Aquarium Heater, 800W/1200W fish tank heater, double tube heating, rapid heating and energy saving, LED digital temperature controller, suitable for sea water and fresh water(1200W)
HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic
AquaMiracle Mini Aquarium Heater 5V/2A USB 10W Small Fish Tank Heater for Tanks up to 1 Gal, Digital Display Thermostat Betta
AquaMiracle Aquarium Heater 100W Fish Tank Heater for 10-20 Gal Tanks, LED Digital Display Thermostat Turtle Heater with Out-of-Water Auto Shut-Off, Overheat Protection & Memory Function