
Orlushy Submersible Aquarium Heater
Precise temperature dial from 68 to 89F allows for complete control of aquatic climate within a 1-degree difference.
The Orlushy Submersible Aquarium Heater is a reliable option for a 100W aquarium heater, and the 2-cup design makes it easy to hide in the tank. The heater also shuts down automatically if it's set too high, so it's a great way to prevent dangerous overheating. The 2-cup design also makes it easy to add water to the heater, and the heater also shuts off automatically if it's set too high, so it's a great way to prevent dangerous overheating. The heater is also very accurate, with an accuracy of 0.1°C, so it's easy to set the temperature exactly the way you want. The heater is also very quiet, and the 2-cup design makes it easy to add water to the heater. The heater also shuts off automatically if it's set too high, so it's a great way to prevent dangerous overheating.

PULACO 25W Small Aquarium Betta with Heater Free Thermometer Strip
Quick and Easy Installation:Vertical or horizontal placement using, Aquarium heater automatic temperature control 78, no need to adjust temperature, easy to operate, fishes happy.
The Pulaco Betta Heater is ideal for tanks up to 1-6 gallons. It's easy to use, and it keeps the tank water at the right temperature. It's compact and light enough to leave on the tank all the time, and it's inexpensive. The only drawback is that, like most small heaters, it's noisy. You can position it under a glass hood so it can vent outside, but that will reduce the heater's effectiveness. Overall, though, we recommend the Pulaco Betta Heater for tanks up to 6 gallons.

FREESEA 25 Watt Aquarium Betta Fish Heater Tank with Aquarium Submersible Thermometer
Temperature range: 63F~95F , It is very easy to adjust the temperature you need, we also deliberately give each customer a free diving thermometer, you can observe the water temperature of the fish tank at any time.
The Freesea 25 Watt heater is our favorite pick for aquariums up to 5 gallons. It's inexpensive, and while it's a bit noisy, it's quiet enough not to bother fish or people in the room. It's also well built, with a sturdy plastic body that resists corrosion. The heater has accurate controls, with temperatures displayed clearly on the digital display. The heater's automatic safety shut-off feature prevents it from overheating, and the heater has a wide temperature range, so it could be used in aquariums of any size. The heater has suction cups on the bottom, which hold it securely in place in the aquarium, and it moves easily as well. The heater is submersible only, so it can't be used in aquariums where it's necessary to have a traditional heater sitting on a shelf above the aquarium water.

HITOP 25W 50W Adjustable Aquarium Heater
Accurate Temperature Control: This fish tank heater built-in thermostat, will automatically keep the water at the set temperature within2F error. Comes with an sticker thermometer to detect water temp at any time.
The HITOP 25W 50W aquarium heater is our top pick for budget buyers. It is bigger than most aquarium heaters, and the built-in thermostat helps it maintain the temperature you set, which is a definite plus. The heater is 33% thicker than most, which means its heat output is more stable and less likely to interfere with fish. The heater also has a built-in safety feature, which shuts off the heater if the water temperature gets too high. Its 50W output helps it heat larger aquariums. The heater has an adjustable temperature range of 68–93 F, which is more than most heaters, and it comes with the power chord you need to run it. The heater comes with a suction cup for mounting, but it's fairly large, so you'll have to mount it somewhere out of the way. Overall, the HITOP is a solid, reliable choice for small aquariums.

JamgoZoo Aquarium Heater with 100W/200W/300W/500W Thermostat: Fish Tank Heater
Easy to Use and Hide- Submerge the heater in water, connect the to the power supply and set the temperature to start heating. In addition, the detachable shell design allows it to be placed in a narrower space to maintain your overall decoration style.
The JamgoZoo 200W Aquarium Heater has one of the best temperature controls we've seen on a heater. It heats quickly and precisely, and you can adjust the temperature in 1-degree increments. The heater's digital display is easy to understand, and the buttons on the heater's exterior are easy to press. The JamgoZoo 200W Aquarium Heater has two temperature units, one Celsius, and one Fahrenheit. The Celsius unit makes it easy to set a lower temperature, and the Fahrenheit unit makes it easy to set a higher temperature. The JamgoZoo 200W Aquarium Heater comes with a 6-foot power cord, a remote temperature sensor, and an instruction manual. The temperature sensor has a 5-foot cord, and the remote temperature sensor has a 10-foot cord. The JamgoZoo 200W Aquarium Heater's heating element is made of high-quality refractory ceramic, and it is produced in China. The heater's outer casing is made of high-quality plastic, and it can withstand splashes of liquid. The JamgoZoo 200W Aquarium Heater has a 1-year warranty.

VIVOSUN 100W Aquarium Heater Submersible Titanium Fish Tank Heaters Intelligent with LED Temperature Display and External Temperature Controller
Easy to Setup: 100W submersible heater is suitable for 13 to 25 gallons aquariums; Vertical or horizontal installation and ensure the device is fully submerged underwater
The VIVOSUN 100W Aquarium Heater Submersible Titanium Fish Tank Heaters with Intelligent LED Temperature Display and External Temperature Controller is an affordable, well-performing heater that is suitable for most aquariums. It's well built and functions as designed. The titanium tube is sturdy and resistant to corrosion, and the heating element is located inside the titanium tube, so it's protected from water. The heater is sturdy and durable. The controls are intuitive and simple to use, and the built-in display helpfully shows the temperature, so you no longer need an external thermometer. The heater is easy to install. The heater is 110V, so it can only be used with 110V power supplies.

SZELAM 500W Aquarium Heater Submersible Fish Tank Heaters with Temperature Intelligent Probe and LED Display External Temperature Controller
Built with Overheat and Water Shortage Protection. This submersible aquarium heater is more sensitive and intelligent to resist overheat and water shortage than traditional glass heaters and it is automatically power off when taken out from water.
The SZELAM 500W Aquarium Heater Submersible Fish Tank Heaters with Intelligent Temperature Probe and LED Display External Temperature Controller,for Fish Tank 79-120 Gallons is, simply put, a workhorse of a heater. It's packed with features, and it's well built--an excellent choice for any aquarium. The heater is submersible, so it doesn't matter where you place it in your tank; it'll survive in even the deepest of waters. The heater's temperature probe is accurate, and its display is bright and easy to read. The heater has an external temperature controller, which makes it easy to adjust the set temperature from outside the tank. The heater has adjustable temperature settings, from 79 to 120 degrees Fahrenheit, and you can set the temperature in 1 degree increments. The heater has 2 independent power settings: 500W and 500W max. It's not unusual for aquarium heaters to have 2 power settings, but it's nice to have the extra option, especially for larger tanks. The SZELAM 500W Aquarium Heater Submersible Fish Tank Heaters with Intelligent Temperature Probe and LED Display External Temperature Controller,for Fish Tank 79-120 Gallons is backed by the manufacturer's 2-year warranty.

FREESEA Aquarium Fish Tank Heater: 50 Watt Adjustable with Thermostat 2 Suction Cups & Thermometer for Betta Tank
High Quality: This upgraded aquarium heater now updated for 2mm durable Quartz Glass, which is pretty shatter-proof and blast-proof and prevents electricity leakage. And the stronger protective container updated for Anti-melting anti punching double sealed material, it is scald-preventing for your pets and your safety, suitable both for fresh and salt water.
The Freesea Aquarium Fish Tank Heater is a compact, 50-watt aquarium heater that is ideal for small tanks up to 15 gallons. The heater automatically switches on and off when the temperature reaches or falls below the set value, and also has a safety shut-off feature to prevent overheating. The heater has a digital temperature display, and the controls are intuitive. The heater is nice and compact, and it fits nicely in the corner of the tank. The heater has high and low settings, and it stays cool to the touch when it's on. The heater uses tap water, so it doesn't use extra water, and the automatic shut-off feature ensures that the heater won't run unnecessarily. The heater runs quiet, and is easy to install. The heater only uses 1.5 watts of power when it's off, and the heater has a 1-year warranty.

BOEESPAT Small Aquarium Heater 50W Fish Tank Heater for 5/10 Betta Gallon Fish with LED Temperature Controller and Smart Thermostat
50W Compact Fish Heater110-120V/60HZ square shape design small aquarium heater, fast heating for small fish tank. 50W tank heater is for 3-10gallon, 100W tank heater is for 10-20 gallon. The power cord is 5ft, long enough for use indoors. With 2 strong suction cups at the back side of the betta heater, it's easy to install it on to glass, acrylic or plastic tank
The BOEESPAT small aquarium heater is reliable, easy to use, and compact, and it's among the least expensive options for maintaining your tank temperature. The heater has an intuitive digital control panel, and it's simple to set and maintain your desired temperature. The heater is small enough to fit inside most tanks, and it has an integrated temperature sensor that automatically adjusts the water temperature when the tank becomes partially or fully submerged. The heater's reliability was impressive, and it never failed to maintain the temperature we set. The heater's small size and ease of use also make it a great heater for small tanks, such as small freshwater and saltwater tanks, and as a turtle tank heater. The heater's LED temperature display blinks red, green, or blue, depending on the temperature, and it's easy to read. The heater's red light indicates that the heater is heating and that the temperature setting has been reached, and the blue light indicates that the heater is stopped and that the water temperature is below the setting. The heater's external temperature controller allows you to set the temperature from outside the tank, and the heater's temperature sensing accessories will automatically maintain the water temperature. The heater will restart heating when the water temperature is 1 degree below the temperature you set. The heater's compact size and ease of use make it a great heater for small tanks, such as small freshwater and saltwater tanks, and as a turtle tank heater. It's also inexpensive, and it's among the least expensive options for maintaining your tank temperature. The downside to the heater is that it runs continuously, and the light indicator on the heater's front isn't bright enough to illuminate a dark tank. If you don't want your tank to overheat, the heater's red light is a bad feature. The heater also doesn't come with a temperature probe, so you'll need to buy one separately.

BinChang Submersible Aquarium Heater Fish Tank Heater with Dual Temperature and Displays Temp Controller Adjustable for Turtle Betta Fish Tank
[External temperature controller] This diving aquarium heater is designed to control the external temperature, allowing you to conveniently and safely adjust the temperature without taking the heater out of the water and taking risks.
We were impressed by the Submersible Aquarium Heater's build quality and relatively silent operation. It's easy to install (the instruction manual is very clear, and it's simple to install the heater), and it's fairly reliable. The temperature control is also reliable, and it displays both the current temperature and the target temperature simultaneously. The heater's performance also seemed consistent, and it kept our 40-gallon tank at a steady 72 degrees, which was warm enough for our fish. The Submersible Aquarium Heater's biggest downside is its power cable, which is a bit too short. When sitting more than a few inches away from the heater, the power cord was too short to reach my power switch, so I had to unplug the heater and plug it back in whenever I wanted to adjust the temperature. The heater also takes a long time to heat up. It typically took about 45 minutes for the heater to reach 75 degrees, which is more than half an hour longer than other heaters we tested.