Best Small Aquarium Heaters in 2025

★100W aquarium heater is suitable for 10 to 20 gallons aquariums,Length - 9",voltage 110-120V, power cord is 6ft, please choose the right wattage aquarium heater according to our size chart.

★It shows an area to adjust the temperature. It's not exactly accurate but it turns easy and can be adjusted at small intervals

★Explosion Proof: 2mm thickened quartz glass,can be used in fresh water and salt water aquariums,easy to hide in the tank.

All Tetra HT heaters have indicator lights to let you know when the heater is on. It will be red when heating and green when the proper temperature has been reached.

The HT20 uses a built in electronic theromstat to automatically maintain water at 78° F which is ideal for most tropical fish. No adjustment is requried.

Ideal for aquariums between 10 to 30 gallons with hoods or glass canopies

Superior Safety and Enriched Ambiance: The fish tank heater is constructed with high-quality shatterproof glass and BPA-free plastic, ensuring a safe habitat for your fish. Aquarium heater 50W, power cord 4.75ft, designed for most fish tanks, recommended for aquariums up to 100 Gallons.

Precision in Temperature Control: This aquarium heater excels in providing a customizable temperature range of 68°F-93°F, catering to various aquatic species. Suitable for freshwater and saltwater tanks, it creates a natural environment for your finned friends.

Compact, Versatile, and Efficient: Whether you have a small aquarium heater 5-gallon tank or an aquarium heater 55-gallon setup, this compact heater can be placed horizontally or vertically. Position near a filter or pump for even heat distribution.

★【Betta Heater】This Fish Tank Heater should be 100% submerged into water, Ideal for small glass or acrylic desktop aquariums up 1 to 6 Gallons, not suitable for less than 1 gallon tank.

★【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.

★【How it Works】: Plug in, red light turns on, the heater will start working until water temperature up to 78°F, and red light off, then the green light will turn on, heater stop working and keeping constant temperature 78°F. Accuracy：±3°F

Aquarium heater with dual temperature sensors provide accurate and real-time water temperatures

LCD temperature display available in both Fahrenheit and Celsius; with a range of 68 to 93 degrees Fahrenheit

Fast heat technology built with a safety shut-off and integrated fish guard to protect fish and invertebrates

【Super Mini Size, 50Watt for 3-10 Gallons】 YukiHalu 50W aquarium heater is designed for 3-10 gallons mini fish tank. Compact design, take less space in the fish tank, easy to hide in the tank. Temperature can be accurately adjusted from 64 to 93°F. This heater suitable for both saltwater and freshwater. The rated voltage is 100-130V.

【Automatic Constant Temperature with 1℉Accuracy】Thanks to advanced Intelligent Frequency Conversion Technology, the water temperature can be kept constant with an accuracy of 1℉. The heater's working frequency will be changed according to temperature variation, and the heating is automatically stopped when the set temperature is reached. Compare to traditional heater, this new technology will cut down 49% electricity bill for you.

【Overheating Protection, Out of Water Protection】The power will be cut off and stop heating automatically if the heater out of water or overheating. Protect your fish. Never cook your fish. 30days full refund, 12-months warranty.

🐟 100W aquarium heater, length 8.8-inch, power cord 4.9ft, designed for small fish tanks, recommended for aquariums 15 to 30 Gallons.

🐟 Adjustable and easy to use: This aquarium heater, adjustable temperature range 68 ~ 93 °F, after setting the temp you want, will on or shut off automatically when the water temperature changes, no extra adjustment is required.

🐟 Accurate Temperature Control: This fish tank heater built-in thermostat, will automatically keep the water at the set temperature within±2°F error. Comes with an sticker thermometer to detect water temp at any time.

🔥【Explosion-proof Quartz Glass Aquarium Heater Durable and Safer】The heater made of explosion-proof quartz glass material and a high-temperature resistant nickel-chromium heating wire with silicon carbide heat conduction,faster water heating and long lasting.2 hours heating 1℃.The shell is a high temperature resistant PC material, which can effectively protect the fish from scalding.

🔥【Temperatures Ranges 68℉ to 93℉,Automatic Heating】The heating rod built-in thermometer,When the water temperature is lower than the set temperature by 1℉, the heater will automatically heat up, and stop heating when the water temperature is consistent with the set temperature.Fahrenheit and Celsius can be converted to each other,Pressing and Press and hold "+" and "-" at the same time, Fahrenheit and Celsius will be converted into each other after 5 seconds.

🔥【LED External Controller with Indicator Light】The controller is not waterproof, please keep away from water，LED digital display screen shows the current water temperature and preset temperature.The number the left on the controller is the current water temperature, and the number on the right is the set temperature,torch light and surrounding lights flicker means heating,torch light and surrounding lights not flicker indicate constant temperature.

【Aquarium Heater 200W】-- The 200W aquarium heater produces stable power with quick heat up. It's length is 8.3'', voltage 110-120V, power cord is 5.9ft (cable wire: 4.6ft, power wire: 1.3ft) . Aquarium heater for 20 to 40 gallons, ideal uses for the marine saltwater and freshwater, fish tanks, turtle tanks, betta tanks, small ponds, and so much more.

【Safe and Durable Fish Tank Heater】--The components of this 200W fish tank heater are designed for safety and durability, and encased in a high-durability ABS shell. The nickel-chromium heating wire and quartz glass are made of high-temperature resistant materials, along with explosion-proof quartz sand, giving the product a high level of safety and durability.

【Comprehensive Protection Submersible Aquarium Heater】 -- Our submersible aquarium heater have 2 intelligent protector to avoid damage to the product and its circuitry. ①Over max temp warning, when the temperature is higher than the maximum temperature 94℉/34℃, the code HH appears and automatically stop heating. ②Off-water warning, when the submersible aquarium heater is higher than the level of the fish tank water code E1 appears and automatically stop heating.

🐠25W Betta Aquarium Heater: Creating and maintaining a perfect and comfortable water temperature for our cute fish is not easy, which requires a lot of effort. Now DaToo MINI 25W Aquarium Heater can help you make this easier. Precise and constant temperature, no need to set, keep the temperature of fish habitat in the best state at all times. You will find it very easy and happy to take care of pet fish！

🐠Precise And Constant Temperature: No need to set, DaToo Fish Tank Heater will automatically keep the water temperature of the fish habitat at 78℉. This temperature is very suitable for betta and most tropical fish. When the water temperature is lower than 78℉, the heater starts to heat and the red light is on. When the temperature reaches 78℉, the heater stops heating and the green light is on. DaToo will always maintain this comfortable temperature for your beloved fish!

🐠The Smallest 25W Betta Heater: For most fish lovers who have small fish tanks of 1 to 5 gallons, a small heater means more space for fish. This is the smallest 25W aquarium heater on the market, only 0.2 inches. No matter how small your fish tank is, it can be used perfectly in it, and you can't even find it. Very MINI!!

This 50 watt heater is for aquariums up to 12 gallons. Adjustable temperature dial allows you to set the temperature 1 degree with every click.

Thermal Switch automatically turns off as temperature rises above an internal preset and turns back on once it cools down.

The advanced heating element contains a mica core surrounded by a mesh heating element for superior heat transfer with enhanced durability

【Run Dry Protection】This egg-shaped small aquarium heater automatically shut itself off once it come out of water which ensures the safety of your pet, especially turtle and frog

【Protective Guard】Made of high quality quartz glass, waterproof double seal material, covered with protective case, shatter-resistant construction, this fish tank heater keep your fish from scalding and punching

【Digital LED Display】External temperature setting control avoids getting hands wet, digital LED display shows real time water temperature. Heating temperature range from 63 to 94°F. Control accuracy is +/- 1°F.

FULLY SUBMERSIBLE AQUARIUM HEATER: The 25W Cascade Aquarium Heater easily maintains healthy water temperature within a 1° accuracy, and can be set anywhere between 68 ℉ and 89 ℉, by using the red control knob. The 25W model works great for fish tanks up to 5 gallons.

VISIBLE & ACCURATE TEMPERATURE SCALE: With an easy to read setting scale in both Celsius and Fahrenheit, it’s easy to see the temperature adjustments being made. To increase the temperature, rotate the control knob counter-clockwise, and to decrease, rotate it clockwise; or, follow the + and – symbols located near the control knob.

ORANGE PILOT LIGHT: Our Cascade Heat Aquarium Heaters feature a pilot light that indicates the heating cycle status. This means that it will go on and off by itself as the thermostat cycles the heating element on and off. In other words, orange light = heater is on. Similarly, these aquarium heaters make a faint click when turning off.

【50Watt Heater】This Aquarium heater is suitable for 8 to 16 gallons aquariums, voltage 110-120V/60Hz, power cord is 5.0 ft, please choose the right wattage aquarium heater according to our size chart.

【Temperature range】: 68°F to 93°F (20°C - 34°C) , It is very easy to adjust the temperature you need (Temperature accuracy: ±3℉). we also deliberately give each customer a Thermometer Sticker you can observe the water temperature of the fish tank at any time.

【Safety & Blast Resistant】2mm thickened quartz glass, 33% thicker than the normal, safer for both human and pet, heater can be used in fresh water and salt water aquariums,easy to hide in the tank.

🐠DIGITAL DISPLAY & EXTERNAL CONTROLLER: Easy to use, LED digital display, external hand controller, press 1 time adds 1 degree, can be set between 59℉(15℃)~93℉(34℃), easy to know the real-time temperature. The working status can also be displayed, red light on: heating, green light on: constant tempe.

🐠ANTI-DRY PROTECTION: Intelligent temp sensing, when the heater is exposed to air, display ER fault code and the heater will shut off automatically. When the heater is completely immersed in water, it will start working automatically. Effectively extend the service life. It has a power-off memory function and no need to set it again.

🐠OVER TEMPERATURE PROTECTION: Intelligent induction device, stable work, good performance, over-temperature protection, avoid cooking fish due to high temperature. When temp pass 95 °F, the LED display showsflashing 95 number code, red and green light flash together, the heater will shut off automatically.

【Auto Shut Off】 ①Automatic overheat system will shuts the unit off when the water temperature over 95°F. ② Running dry protection will shut off unit when the heater rod out of water. ③ The power cord 6.3 feet in length and is UL listed.

【Adjust the Temperature to Your Needs】 Equipped with an Intelligent IC temp controller, which will turn the heater off when it reaches a preset temperature and turn the heater back on when the temperature dips below the setting. Adjust the setting of temperature from 59℉ to 93℉ to keep aquarium proper temperature.

【 At-a-Glance Temperature Monitoring Controller】 Build in LED temp controller shows both set temperature and real time water temperature . Red indicator light turns on when heating and turns blue in the situation reached set temp or failure alarm. It can be accurate enough to keep temperatures with +/- 1 degrees.

SUPER MINI SIZE – This small aquarium heater is “thumb size” - only 2.36” (6cm) in length. Great for nano tanks / betta tanks. The innovative super mini size perfectly solves the headache of the fish keepers on the traditional heaters! Takes up less space, easy to hide, but in full power! Temperature range is 64-93F, for 1-2 Gallon tanks.

ACCURATE TEMPERATURE – Thanks to the intelligent inverter technology, with the in-built chips this thermostat keeps the heater at a constant temperature at an accuracy of 1F, much more accurate than the traditional knob-controlled heaters. The thermostat shows 2 readings – the current temperature and the set temperature – very easy to operate.

DRY RUN / OVERHEATING PROTECTION – Full consideration of safety. With the multiple protections this fish tank heater will stop working when the water level is lower than the minimum water level or when the water temperature exceeds 97F. You are free from “cooking fish”!

🐟HITOP Mini size aquarium heater 25W with controller, suitable for seawater and freshwater heating, betta fish and turtle tanks and other small fish tanks or fish bowl 1-6 gallon.

🐟Easy to operate: This fish tank heater is easy to use, 6Ft long cable wire and the external controller can easily set the temperature, and the temperature adjustment range is 68-93℉.

🐟Easy to read temperature: The controller of this heater has Digital LED temperature display, which can display the real-time water temp and set temp, so that you can know the temperature changes in the fish tank easily. There is also a clear heating indicator on it.

🐠【Rapid Heating and Two Temperature Control System】300W aquarium heater is sutable for 40-70 gallon fish tank and made of the most stable nickel-chromium heating wire, which can quickly and stably conduct heat to the surroundings. It has a built-in temperature control system of Fahrenheit and Celsius(Temp range: 68-94℉/20-34℃). You can press and hold the button next to the controller to switch.

🐠【Intelligent Water Sensor and Automatic Power Off】This fish tank heater has a unique intelligent temperature and water sensor system, the heater will automatically stop/restart heating when the heater is completely out of /in water. and will stop when it rapidly heats beyond the set temperature.

🐠【Explosion-proof Titanium Alloy Tube Aquarium Heater】The submersible aquarium heater is made of explosion-proof Titanium Alloy material and a high-temperature resistant nickel-chromium heating wire with silicon carbide heat conduction, faster water heating and longer lasting.

🐠【New Upgrade】- The 300 watt fish tank heater is suitable for 50-80 gallon fish tank. Double tubes heating element, made of two silicon carbide heating tubes and quality plastic cover for fast, steady, more evenly distributing heat.. IP68 waterproof, explosion-proof and anti-corrosion make it stronger than normal glass and metal heater. Your Fish will be no longer afraid of winter.

🐠【Safety Guarantee】- With anti-dry heating protection and overheating protection, when the water temperature exceeds 93℉, the adjustable aquarium heater will stop heating and alert. It will also stop when the water level is 5cm lower than the heater and the display will display "E1". Escorting your pet's safety all time.

🐠【Smart Temperature Control】- Accurate temperature controls within 1°F difference. The heater will stop heating when the temperature reach the setting and restart when lower than setting. If power is shut off,the memory function will keep the temperature settings until it powers on again. Always provide the best living environment for our cute fish.

PERFECT MINI HEATER FOR 1~1.5 GALLON TANK - For a Betta breeder with a 1 to 1.5 gallon small tank, it is very difficult to choose a suitable heater. Because most of the heaters on the market are too big for this small tank. This not only affects us to watch our beautiful Betta, but also reduces the activity space of the Betta. Now DaToo Mini Aquarium heater can help you solve this problem. Ultra-small and thin size, perfectly hidden in a 1~1.5 gallon tank, your Betta will be happy with it! !

CONSTANT TEMPERATURE & NO NEED TO ADJUST - DaToo 10W MINI Aquarium Heater can automatically maintain a constant temperature between 75°F and 82°F (depending on the external environment), no need to set. This temperature range is ideal for most tropical fish and is very beneficial for the reproduction of betta and promotes their metabolism. With no extra work, just plug it in and the DaToo 10Watt Small Fish Tank Heater will help your fish stay healthy and comfortable. Great for kids!!

24V SAFE VOLTAGE & POWER OFF AFTER LEAVING WATER - The output voltage of the DaToo Betta Heater is only 24V, which not only ensures the safety of the fish, but also ensures the safety of the user. No need to worry about leakage, you can rest assured to use it for your children. The Betta heater needs to be completely submerged in the water. If it leaves the water, it will automatically stop heating to prevent dry burning (heating indicator is green), which is very safe.

The Slim heater will increase the water temperature of mini aquariums up to 10 gallons by a few degrees compared to the ambient room temperature; The Slim heater can be used in glass, acrylic, plastic fish bowls and aquariums; Safe to use under gravel; Please note, Slim heaters are not suitable to be used in environments without water

Extra small slim fish tank heater is a great choice for Betta fish & suitable for fish tanks 2 to 5 gallons, measures 3.5-inch diameter, 7.5 watt; Plug and Play universal fish tank heater; No temperature to set; slim heater provides warmth for betta fish without taking up much room

Heater can easily be placed submerged in water or even under the tank gravel; The 90 degree angle makes this great for Betta acquariums; Safe to use in glass, plastic and acrylic fish tanks

Hydor Theo 25-Watt Aquarium Heater is a fully submersible; shatter-proof glass aquarium heater ideal for 2-to-7-gallon fish tanks; measures 7 inches long

Maximum Safety Aquarium Heater; THEO fish tank heater is shock resistant thanks to the patented PTC heating element and the shatterproof glass tube

Free positioning in aquarium with supplied suction cups; The Theo aquarium heater can be placed in the fish tank vertically, horizontally and fully submerged

SMALL AND POWERFUL: This mini aquarium heater is about 2 "long, and is super small. It is specially designed for small fish tanks and does not occupy any space. Upgrade the chip to make the temperature sensing more sensitive and the temperature rise more accurate.

INTELLIGENT MEMORY FUNCTION: After setting the target temperature, the power is suddenly turned off, and the target temperature remains unchanged after turning on the power again.

OVERHEATING PROTECTION: Built-in temperature sensor, temperature range 64-93°F. If the water temperature exceeds 95°F, the error code "HI" appears, the heater stops working, and when it returns to below 95°F, the error code disappears and it starts working again.

[Digital dual temperature display] This HITOP 600W aquarium heater adopts a digital temperature control system, so it can display the set temperature and real-time power at the same time, which is clear to read. There is also a heating indicator to indicate the working status. For tank 75-180gallon.

[Titanium alloy heating element and shatterproof] The heating element is made of titanium alloy, which is strong and corrosion-resistant compared with other materials, so it is shatterproof and can be used in both freshwater and seawater. The impact-resistant sturdy cover makes this heater very suitable for large fish tanks and turtle tanks.

[External controller] No need to take out the heater from the fish tank to set or adjust the temperature, you can operate it through the external controller of this fish tank heater, easy to use. The temperature setting range is 64.0°F~93.0°F (18.0°C~34.0°C).

✅Upgraded Heater - Our aquarium heater is made of high quality real quartz glass material, will not explode during working, can totally keep your fish safe and health, suit for freshwater and saltwater tank.

✅Circulating Working Mode - Our submersible aquarium heater has a super good feature is after setting your temperature, it will work about 5-10 minutes, then stop 2 minutes, then continue to working, repeat this working mode until get your temperature. This working mode avoid overheating your fish.

✅Adjustable Temperature – The temperature of the water heater can be adjusted, rotate the orange dial can easily set the accurate temperature which you want. Temperature range is 20-34 c(68-93 F).

🐠【50W Compact Fish Heater】110-120V/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

🐠【Shut off When Out of Water】BOEESPAT aquarium heater adopt newest technology, it is a fully submersible aquarium heater for fresh water and saltwater tank, when the top part of betta fish heater is out of water it will be forcibly stopped. After putting it in the water again, the fault disappears and normal operation resumes.It is a safe and reliable water heater tank

🐠【Small Aquarium Heater with External Controller】You can set the temperature outside the fish tank through the external controller, and the fish tank accessories of temperature sensing built in will cyclic heating the tank water automatically .Temp range from 65℉ to 93℉. Every time you set your betta fish heater, just press the button over and over until it reaches to your desired temp, then stop and wait the digit flashing for 3 times, then setting is done

Heating uniformly and high heat transfer efficiency, protect your fish from the cold

Quartz glass material makes it extremely durable, wide range of applications and suitable for various aquariums

Powerful suction cups makes it easy to install and place, ensuring heater runs smoothly in the aquarium

Ensure your turtle grow and thrive --- It is absolutely essential that your aquarium should be heated between 72° and 77°F day and night for optimal comfort and metabolic efficiency of your turtle. Any temperature below 72°F will cause your pet to enter a state of minimal activity and they will be stressed and miserable. Make sure your amphibians are at their optimal performance with this heater.

Fully submersible water heater --- This 10-watt aquarium heater supports 1.5 gallons (5 liters) turtle tank. Its exterior is designed tougher than glass and the sealed polymer can be submerged into your tank. The heating element is surrounded by a thick plastic to ensure protection of your turtle. It has a non-corrosive shell for strength which makes it nearly indestructible.

Automatically reaches the perfect present temperature --- The smart Turtle and frog heater by SunGrow has a built-in electronic thermostat to automatically maintain water around 80°F which is ideal for most side-necked and hidden-necked turtles. It saves you from the trouble of constantly keeping a check on the temperature of your tank. It will automatically shut down when it reaches around the desired temperature, no manual adjustment is needed.

SUPER MINI SIZE – This small aquarium heater is “thumb size” - only 2.36” (6cm) in length. Great for nano tanks / betta tanks. The innovative super mini size perfectly solves the headache of the fish keepers on the traditional heaters! Takes up less space, easy to hide, but in full power! Temperature range is 64-93F, for 1-2 Gallon tanks.

ACCURATE TEMPERATURE – Thanks to the intelligent inverter technology, with the in-built chips this thermostat keeps the heater at a constant temperature at an accuracy of 1F, much more accurate than the traditional knob-controlled heaters. The thermostat shows 2 readings – the current temperature and the set temperature – very easy to operate.

DRY RUN / OVERHEATING PROTECTION – Full consideration of safety. With the multiple protections this fish tank heater will stop working when the water level is lower than the minimum water level or when the water temperature exceeds 97F. You are free from “cooking fish”!