Best Submersible 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

Aquarium heater that blends into the aquarium environment with built-in reflective technology that mirrors the surrounding colors

Computer-calibrated thermostat and easy-to-adjust temperature control dial

Shock resistant Borosilicate glass and high density ceramic heat sick

Fully submersible

Thermo safey control protects against running dry

Will automatically turn off when water level dips too low

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.

Explosion Proof: The aquarium heater is made of 2mm thickened quartz glass, 33% thicker than ordinary glass, explosion-proof, not easy to crack, which is very safe for people and aquatic animals.

Application: 300W water heater is suitable for 35–70 gallon tank, also suitable for both saltwater and freshwater, suitable for fish tanks and turtle tanks, must be completely submerged in water when using.

Accurate Temperature: The fish tank heater can be adjusted from 68°F to 93°F (20°C - 34°C), comes with a thermometer sticker, convenient to detect the water temperature without another pay.

Adjustable heat setting 68 to 88°F, Electronic Thermostat accurate to +/- 1°

Shatterproof and nearly indestructible

Fully submersible; Auto Shut-Off when over-heats, resets when it cools down

Preset to 78°, accurate to +/- 1°

No adjustment required

Shatter resistant

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.

Fully Submersible. Power: 300W. Suggested water volume: 55-100 gal.

Adjustable Temperature: The temperature of the fish tank heater can be adjusted automatically. Temperature setting range: 65° F - 93° F(20°C~34°C), and the display is easy to read.

High Quality: Aquarium heater made of high quality quartz glass, double seal material , advanced design, ensures safe operation.Fully suiting for fresh or saltwater aquariums, provide a constant warm environment for your tropical fish to stay healthy.

🔥【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.

FREESEA Aquarium Heater: 75w betta fish heater, voltage: 110~120V, is suitable for use in 5-15 gal betta fish turtle tanks and aquariums. The power cord is 5ft, long enough for indoor use

Double Safety Protection: When the top part of the turtle tank heater is out of water it will auto shut off. When the actual water temperature is higher than 94°F, it will auto activate the overheating protection and stop heating

External Controller: The betta fish heater is adjusted by an external controller, which you can mount on the outside edge of the tank. It’s convenient to adjust temperature that range from 63℉ to 94℉

THERMAL SWITCH: Automatically turns off when temperature rises above an internal pre-set and turns back on once it cools down.

ADVANCED HEATING ELEMENT: Contains a mica core surrounded by a mesh heating element for superior heat transfer with enhanced durability.

MOUNTING BRACKET: Securely attaches to glass and provides three window positions to view the temperature display.

Electronic thermostat from 68°F up to 94°F, accurate to ±0.5°F

AUTO SHUT-OFF circuitry prevents overheating.

SHATTERPROOF outer casing make the NEO-THERM PRO heaters virtually indestructible.

【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 100W 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 100W model works great for 15 – 20 gallon fish tanks.

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.

🐟RAPID HEATING: Faster warming by seconds, the heater material is explosion-proof quartz glass, and nickel-chromium heating wire materials has higher thermal energy efficiency, and then conducts heat through silicon carbide material, is safer and more durable to use. High temperature resistant plastic cover, not easy to deform, and has very strong corrosion resistance.

🐟FREQUENCY ENERGY-SAVING: Auto reduces power when approaching the set tempe, by heated at 10% to 30% power, fully utilizes thermal energy inertia to smoothly reach the set tempe, saving energy. The external controller is easy to operation, every press changes the set tempe by 1℉, ranges from 59℉(15℃) to a max of 93℉(34℃) in order to meet your needs.

🐟INTELLIGENT THERMOSTAT: Over-temperature protection prevents "cooking fish". When the water temp exceeds about 95 °F, flashing 95 number code, red and green light flash together; and over 93℉, the heater will stop heating automatically. When the water temp cool down to below 93℉, the heater will start working auto.

【External Digital Display Controller】With its easy-to-use LED digital screen simultaneously displays the set temperature and the current aquarium temperature. You’ll be able to set temperature up in a healthy range of 59 to 93°F with button and monitor how well the heater is doing its job in real-time.

【Double Tubes Heating Element】Featuring shatterproof quartz glass tube + nickel-chromium heating wire for fast, steady, more evenly distributing heat. With a PC plastic guard to protects your fish touch it they won’t get burnt.

【Running-Dry Shut Off Protection】This is a completely submersible heater that will stop working when exposed to air and display error code "E1", which resets itself to resume working when placed back into the water.

🔥SAFE& DURABLE: Made of heat-resistant quartz glass and PC plastic cover, double seal material, providing explosion-proof, shatterproof, IP68 waterproof, much safer for human and your lovely fishes, your pets will no longer be fear of cold winter.

🔥INTELLIGENT AUTOMATIC HEATING: Automatic constant temperature function, design with External Temperature Controller, Temperature Range is 59ºF- 93 ° F (15 ° C- 34 ° C), Hold button at the top of the controller down for 5 seconds, switch easily from Celsius to Fahrenheit. It will restart to heating when the water temp is 1℉(1° C ) off the set temp. If power is shut off, the heater will keep the temperature settings until it powers on again

🔥DUAL TEMP DISPLAYS: LED display on the middle of the controller front side, Current Temp and Set Temp. If your heater is working properly, the red light will be constant on. When the temperature is reached 93℉(34℃), it will stop work, the blue light will be constant on. When the heater exposed to air and is not fully submerged, then display E1 fault

For 5-10 Gal Tanks: Measure 8.3 inches in length. Applicable for aquaculture and fresh, marine and tropical aquariums. Save your fish or plants from coldness to keep them vigorous.

Adjustable: Controllable temperature range from 68 °F to 93 °F (20-34 °C). Simply rotate the knob to freely regulate the temperature with deviations from ± 2 °F to ± 4 °F.

Detect Temp Timely: With a built-in thermostat, it will automatically keep the water at the set temperature. The extra thermometer sticker allows you to detect water temp at any time.

Preset temperature has been set to 77°F, appropriate for most tropical fish, shrimp and aquatic plants requiring stable conditions

With accuracy of ±2°F and overheat protection, protect your tank from extreme temperature

LED indicator light will turn to red when the heater is actively heating

【For Fish Tank 15-40 gallon】200W aquarium heater, voltage AC 110-120V, power cord is 5.0ft, please choose the right wattage aquarium heater according to our size chart. Comes with detachable shield and 2 suction cups. It's easy to hide it in the tank (acrylic or glass).

TEMP ADJUSTABLE: Temperature can be adjusted between 68-94℉. You can set the temp to one of these values on the dial: 68, 71, 75, 78, 82, 86, 90, 94 by rotating the pointer, which allows for complete control of aquatic climate within a 2-degree difference.

SAFETY PROTECTION: Effectively maintain the tank water in the constant temp you set, stop heating when the water temp is 1.5-2℉ above the set temp and restart heating when the water temp is 1.5-2℉ below the set temp.

25-Watt submersible heater for freshwater or saltwater aquariums

Easy to read temperature settings

Impact-resistant glass design; waterproof sealing

Fully submersible, auto shut-off when overheats, resets when cools down

Electronic thermostat stops heating once set temperature is reached

Precise temperature setting adjustable to 1° F (68-88° F)

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.