Best 100 Watt 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

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

★【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

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

🐟 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.

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.

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.

Heating Protection: Its indicator light turns red during working and automatically shuts off to stop heating when reaching the set temperature. No danger of overheating to your aquatics.

【Aquarium Heater 500W】-- The 500 watt aquarium heater produces stable power with quick heat up. It's length is 10.6'', voltage 110-120V, power cord is 8.2ft. Aquarium heater for 75 to 120 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 500W 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.

This 100 watt heater is for aquariums up to 29 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

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.

【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.

【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.

🐠【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.

Hydor Theo 100-Watt Aquarium Heater is a fully submersible; shatter-proof glass aquarium heater ideal for 14-to-26-gallon fish tanks; measures 8.9 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

[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).

DaToo Aquarium Heater: How to make our beloved fish live in a comfortable environment? This is a matter of concern. No suitable temperature, our fish will not survive healthy. The DaToo Submersible Aquarium Heater is a system that create a warm and comfortable living environment for your lovely fish. Select DaToo Aquarium Heater, Let us care about your fish starting from the temperature.

Adjustable Temperature: Only need turn the knob on the top of the DaToo aquarium heater, You can easily get the temperature you want（68 to 93°F) and you can read the temperature you set by the dial of the aquarium heater. Thermostat system to ensure that your beloved fish can be happy and comfortable life

Sturdy And Durable: Still worried about the heater will be broken?Now let's say goodbye to this worry. The shell of the DaToo Aquarium Heater is made with Shatterproof, Corrosion resistant, Wear-resistant microcrystalline glass(glass-ceramics), can be used in fresh water and salt water.The heating part is made of nickel-chromium alloy, ensure superior heat transfer and enhanced service life. Select DaToo Aquarium Heater, Let it serve your fish forever..

SUPER MINI SIZE – This aquarium heater is SUPER SHORT in length – might be the shortest heater in the market. It is only a bit more than HALF of the length comparing with the traditional fish heaters! The innovative super short length perfectly solves the headache of the fish keepers on the traditional aquarium heaters! Takes up less space, easy to hide, but in full power! Temperature range is 64-93F.

ACCURATE TEMPERATURE – Thanks to the intelligent inverter technology, with the in-built chips the thermostat keeps the heater at a constant temperature at an accuracy of 1F, much more accurate than the traditional knob-controlled fish 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 (DRY RUN PROTECTION) or when the water temperature exceeds 97F (OVERHEATING PROTECTION). You are free from “cooking fish”!

🐠500 WATTS AQUARIUM HEATER - 500W aquarium heater is suitable for 66 to 135 gallon saltwater and freshwater aquariums. The heater length is 10.8 inches, voltage 110-120V, power cord is 10.1 feet. Please select the appropriate wattage aquarium heater according to our size chart

🐠OVERHEATING & OUT OF WATER PROTECTION - When the water temperature exceeds 94°F or it is lower than the minimum water level, the heater will automatically cut off the power and stop heating, it will display an error code and sound an alarm until the water temperature is below 94°F or the heater is completely immersed in the water. Error code: HH-high temp; LL-low temp; AUTO shut off-out off water. Multiple protection, let you get rid of "boiled fish"!

🐠DIGITAL LED CONTROLLER - Temperature adjustable range: 59℉-93℉, Accuracy：±1°F. You can use the included bracket to mount the controller on the edge of the tank to adjust the temperature without reaching into the water. LED controller shows the current water temperature, preset temperature, working power and more warning sign of Low/ Hi temperature/ Auto shut off. Very easy to operate!

★【300 Watt Heater】: This Aquarium heater is suitable for 10 to 20 gallons aquariums, Length - 10.4 inch, Voltage 110-120V, Power cord length - 51.0 inch, please choose the right wattage aquarium heater according to our size chart.

★【Precisely Temperature Control】: Automatic constant temperature function,with An intelligent chip controls the fish tank heater temperature, making the temperature difference within ±1℃/±2ºF; SALUTE will always maintain this comfortable temperature for your beloved fishes!

★【Temperature range】: 63°F~95°F , It is very easy-to-adjust the temperature you need, and also easy-to-observe the water temperature of the fish tank at any time.

{ RUNNING DRY & OVER-HEAT PROTECTION } This fully submersible fish tank heater maintains proper temperature for your fish in a safety way, auto shut off when over-heats, resets when it cools down. The heater will shut off when removed from the water, and resume functioning upon return

{EASY TO READ LCD DISPLAY} Build-in external temp controller, easy to read LED digital number shows real time water temperature and set temperature. Indicator light let you know when the heater is on. It will be red when heating and green when the proper temperature has been reached

{SHATTERPROOF HEATING ELEMENT} shatterproof titanium tube construct heats fast, nealy unbreakable for freshwater aquariums only. ABS plastic protective sleeve prevents fish from being scald

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)

[Fully Submersible Aquarium Heater] This 100W 110V Strong Quartz Glass Aquarium Fish Tank Heater is suitable for aquariums from 10-30 gallons; includes 150-200cm (5-6.5 feet) cable for easy use. The heater should be submersible fully under the water before turn on

[Explosion-proof Shatterproof Shield-proof Design] Thanks to its high quality Quartz Glass material and its Protective Sleeve, aquarium heater is shatter resistant & more durable than conventional glass heaters

[Provides Accurate Thermal Control] Set and adjust the desired temperature with the use of the Temperature Controller on the top. This allows accurate thermal control via the easy set thermostat for precise

TEMP SETTING GUIDELINE: DO: Rotate left and right to adjust the temperature, easy to adjust, the range is 68℉~93℉. SEE: temperature scale setting guide bar. Working indicator light, plug in the power, the working state is more intuitive.

SAFETY CERTIFICATE: ETL Certification, hygger provide the most effective guarantee for your fish tank. Thickened Quartz Protective Glass; Bottom Protective Cover; Stable Suction Cup; Double Seal; Precision Welding; No Leakage Of Insulation;

WORKING PRINCIPLE: The hygger THERMOSTAT HEATER stops when the surrounding water temperature reaches the set temp, and starts to work when the surrounding water temp is low, and it cycles over and over again to achieve equilibrium. It is not a traditional heater that has been heated all the time.

Durable Titanium Tube - This aquarium heater is made of premium Titanium Alloy, double seal material, advanced design to ensure safe operation. It has explosion-proof function while being also shatterproof and waterproof.

Wide Temperature Range - The temperature of the heater can be adjusted between 20-34℃, 68-93F. It is suitable for many kinds of aquariums, fishes and amphibious turtles.

Easy Viewing and Safe Adjusting - It is easy and safe to adjust temperature by the external controller and the temperature will be shown on the LED screen of the heater.

[Real Smart And Fast Heating]. A good partner for your beloved fishes! SZELAM aquarium heater adopts black quartz sand to conduct heat, which features a high-speed and all-round heat transfer effect that can quickly increase the water temperature. It stops heating when the water temperature is close to the set temperature and continues when the water temperature is lower than the set temperature.

[Upgraded Protective Cover]. The fish tank heater 100w will be a livesaver to your aquatic pets. It will never scald your little fish, as the protective shell is designed with dense small holes, which can protect your fish from being scalded, as well as dissipating the heat to the whole tank.

[Precise Dual Temperature Control]. Both suitable for freshwater and marine water,this aquarium heater 100watt is explosion-proof & anti-scalding. With built-in sensitive temperature control and intelligent heating function, the fish heater can provide accurate and stable temperature when working, while creating a worry-free habitat for your beloved fish.

Safe Rugged Construction -- Built in shatterproof QUARTZ tube wrapped with two heating element mica plate and nickel wire, along with high-impact plastic housing, hygger submersible Aquarium Heater ensures the safety of your pets while maintaining proper temperature.

At-A-Glance Temperature Display -- heater rod shows real time water temperature and indicator light. It will be red when heating, green light when the proper temperature has been reached.

External Knob Controller Memory Function -- allows you quick set temperature without getting hands wet especially in winter, adjustable wide temperature range of 59°F to 93°F in 1-degree increments. Memories last setting when you unplug it to water change.

SUPER MINI SIZE – This aquarium heater is SUPER SHORT in length – might be the shortest heater in the market! It is only a bit more than HALF of the length of the traditional aquarium heaters! The innovative super short length perfectly solves the headache of the fish keepers on the traditional aquarium heaters! Takes up less space, easy to hide, but in full power! Temperature range is 64-93F. 100 Watt for 10 - 20 Gallon tanks.

SUPER ACCURATE 1F – Thanks to the intelligent inverter technology, with the in-built chips the thermostat keeps the fish heater at a constant temperature at an accuracy of 1F much more accurate than the traditional knob-controlled fish heaters and you save your electricity expenses by 50%!

DIGITAL DISPLAY WITH DOUBLE TEMP. READINGS – This fish tank heater comes with an external thermostat with digital display that shows 2 readings – the current temperature and the set temperature – very easy to switch by pressing the SET button and you save an extra thermometer for current temperature measuring.

🔥【110V/60Hz Explosion-proof Quartz Glass Aquarium Heater】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.The shell is a high temperature resistant PC material, which can effectively protect the fish from scalding.

🔥【Temperatures Ranges 59℉ to 93℉,Automatic Heating】The heater 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.Press "+" or "-" once, and the screen will display the set temperature，flashes for 3s and jumps back to the current water temperature.

🔥【Memory Function/Dry Burning/Overtemperature Protection】①No need to reset after power failure, program retains the settings ②when the heater is more than 5cm above the water surface, the error code "Er" will be displayed; when the heater enters the water again, it will return to normal③When the water temperature exceeds 95 ° F, the alarm error code is "95". When the water temperature is lower than 95 ° F, it returns to normal.

【100Watt for 10-20 gallons】YukiHalu 100W aquarium heater is designed for 10-20 gallons fish tank. Temperature can be accurately adjusted from 64 to 93°F. This heater works well in both saltwater and freshwater. Rated voltage 100-130V.

【Compact size】only 13cm/5 inches length for 100W and 150W heater, 19cm/7.5 inches for 200W heater and 23cm/9 inches for 300W heater. Fits mini fish tank, it takes up less space and easy to hide in the tank. Easy to install

【Automatic thermostat at 1°F accuracy】The heater's working frequency will be changed according to temperature variation based on Intelligent Frequency Conversion Technology, and the heating is automatically stopped when the set temperature is reached.