In order to maintain a healthy water temperature range in a 20-gallon fish tank, a 75-100 watt aquarium heater is the right choice. Features like adjustable temperature, safety-shutoff, and easy-to-setup are what you should look for when searching for a good aquarium heater. Following are some of the best options you can choose for your aquarium:
- Best heaters for 20-gallon fish tanks
- 100-watt aquarium heater reviews
- Hygger titanium tube heater with controller
- SeaELF titanium aquarium heater, 100W
- Nicrew preset aquarium heater, cheap and reliable
- Fluval M submersible aquarium heater
- AquaTop titanium aquarium heater with controller
- Orlushy Submersible glass aquarium heater, budget option
- Cobalt Aquatics Flat Neo Heater 75-watt
- Boxtech glass aquarium heater with external controller
- Aqueon Pro submersible aquarium heater
Best heaters for 20-gallon fish tanks
100-watt aquarium heater reviews
Hygger titanium tube heater with controller
- Wattage: 100w
- For tanks: 10 – 25 Gal, both fresh- or salt-water
- Temperature range: 32-104°F, ±0.5°C error, adjustable
- Features: LED digital display controller, thermometer, Celsius or Fahrenheit reading
The Hygger 100-watt titanium aquarium heater is perfect for a 10-25 gallon tank thanks to its exceptional properties. The package comes complete with a submersible titanium heating tube, a separate thermometer probe, and an external controller.
The heater is preferred because its titanium rod is shatter-proof, unbreakable, and provides excellent resistance against corrosion. This makes it heavy duty and perfect for both freshwater and saltwater environments.
Digital temperature controller
It comes with an external electric controller for easy temperature adjustments without getting your hands wet. This external controller displays the current water temperature and also the set water temperature through its build-in LCDs.
It’s very easy to use because its external temp controller is extremely user friendly. Just use arrow buttons to increase or decrease to the temperature you want then press “set”. For switching between Fahrenheit and Celsius just press the up key.
Separate thermometer and heating tube
The feature I love best about this heater is its separate thermometer probe that can be placed far from the heating tube for accurate temperature reading. This ensures the heat is distributed evenly to entire the tank, not only areas around the heating tube.
This heater works perfectly when installed horizontally within the tank. However, be sure to install the heater on the suggested water level. It comes with two suction cups for easy placement.
SeaELF titanium aquarium heater, 100W
- Wattage: 100W
- For tanks: 5-20 Gal
- Temperature range: 68-93°F, ±2°F (20-34℃, ±1℃)
- Features: LCD controller, built-in thermometer, running dry protection
This is also a 100-watt titanium heater with an external controller. Its accuracy in maintaining the water at the right temperature makes it one of the best and most reliable choices for a 5-20 gallon tank.
This heater provides a constant warm through its double heating tubes with premium material that helps your aqua life stay healthy. It’s explosion-proof and corrosion-resistant.
Easy temperature adjustment
It is easy to install and set your desired temperature with the external controller. Just press the “set” button on the external controller until the LED LCD on the heating tube displays your desired temperature.
On the head of the heating tube, there is a small sensor for measuring the surrounding temperature. Its accuracy makes the SeaELF aquarium heater one of the best in quality and performance.
This aquarium heater is also brilliant. It features a running-dry prevention feature, which protects itself from being damaged by operating out of water. The heater displays “E1” if your tank lacks water and stops to continue to heat to protect itself. It only returns to work when being fully submerged in the water.
Nicrew preset aquarium heater, cheap and reliable
- Wattage: 100W
- For tanks: 10-25 Gal
- Temperature range: preset to 78°F, can’t set
- Features: light indicator
This is a submersible glass fish tank heater with an electronic thermostat. It is simple in design and outstanding in quality and performance. It is a cheap and reliable option for those who are on a budget.
The Nicrew aquarium heater does not require any adjustments and its electronic thermostat automatically maintains the temperature at an initially preset of 78 degrees Fahrenheit. The temperature can NOT be set, so ensure the heater meets the temperature need of your aquarium creatures before buying it.
It is straightforward in design that its LED indicator light displays red when actively heating. Its shatter-resistant quartz glass keeps your pets safe.
The heater can be positioned horizontally or vertically based on your preference. However, make sure the heater is fully submerged in water at all times because it doesn’t have a running-fry protection function. It comes with suction cups for easy placement.
Fluval M submersible aquarium heater
- Wattage: 100 watt
- For tanks: up to 30 Gal
- Temperature range: 66-86°F, adjustable
- Features: light indicator, blends into the aquarium environment.
The most exciting feature of Fluval M aquarium heaters is its built-in reflective technology that mirrors the surrounding colors and blends into the aquarium environment. This leaves the aquarium with only a beautiful aquascape, without any obstructive equipment and wires being noticed.
This submersible glass heater is made with high-quality materials. The borosilicate surrounding glass makes it heavy-duty and shock-resistant. The internal high-density ceramic heat sink is one of the best in quality for fast heating and durability.
Its thermostat is computer-calibrated for precise temperature control. This ensures your aqua life is safe by showing accurate temperature readings and maintaining your set temperature precisely. The temperature is adjustable with the dial on its top, making it user-friendly.
The only drawback of this heater is that it contains no monitor for displaying real-time water temperatures. The heater features a slim profile tube for easy placement. It is suitable for both freshwater and saltwater aquariums.
AquaTop titanium aquarium heater with controller
- Wattage: 100 Watt
- For tanks: up to 35 gallons
- Temperature range: 68-92°F, adjustable
- Features: external controller, thermometer probe
The design and build of the AquaTop aquarium heater are basic and easy to access. It comes with a controller, a titanium heating tube, and a separated thermometer sensing probe. It works well for aquariums up to 35 gallons.
The controller features everything you will need to control the working of this heater and monitor the temperature. In the product picture, you can see an LCD displaying temperatures, one power and two arrow buttons for adjustments, two light indicators for the power and the heater. The compact design of the controller makes it versatile to place.
The heavy-duty titanium element construct makes the heating tube highly durable and tough. It is fully submersible and can be installed horizontally or vertically according to your preference. It comes with a pair of suction cups for easy placement.
The wired temperature sensor with its suction cups can be installed remotely in a more convenient location. This ensures accurate temperature reading and even heat distribution in the entire tank.
Orlushy Submersible glass aquarium heater, budget option
- Wattage: 100W
- For tanks: 15 – 30Gal
- Temperature range: 68-89°F, ±1°F, adjustable
- Features: LED light indicator, include a digital thermometer
This is a 100-watt fully submersible glass aquarium heater with a temperature adjustment knob on its top. It comes with a pair of suction cups for easy setup and a digital thermometer for temperature control. It is suitable for both marine saltwater and freshwater.
The Orlushy aquarium heater is explosion-proof thanks to its 2mm thickened quartz glass. Its sensitive and reliable thermostat maintains the desired or ideal water temperature for your aquarium inhabitants. It offers a temperature range from 68°F to 89°F with the accuracy of ±1°F making it ideal for tropical setups.
Overall, the Orlushy aquarium heater is a cheap and affordable option for those who are in shortage of money.
Cobalt Aquatics Flat Neo Heater 75-watt
- Wattage: 75W
- For tanks: up to 20 gallon
- Temperature range: 66-96°F, ±0.5°F, adjustable
- Features: light indicator, built-in thermometer, running-fry prevention
Unlike other glass heaters, the Cobalt aquatics heater is made of resin and thermo-plastic making it nearly indestructible. Its super-flat design is for optimal heating, better heat distribution, energy-efficient, and modern-looking. Its multi-LED display shows both the set and actual tank temperatures simultaneously. The design allows it to face inward or outward.
Cobalt Aquatics Flat Neo Heater
It haves a touch button on the top for you to set the temperature. You can pick a temperature in the range from 66°F to 96°F just by pressing the touch button. And the heater will keep your tank water at the set temperature with minimum fluctuations within 0.5°F of the set one.
Turning off the heater manually during the water changes can be completely forgettable; that’s where the neo-therm safety feature is helpful. It turns off itself automatically when the water levels get too low. This feature prevents the heater from damages by running dry.
Overall, the Cobalt Aquatics 75-watt aquarium heater is unique in design and reliable in performance that makes it one of the best options for your 20-gallon tanks.
Boxtech glass aquarium heater with external controller
- Wattage: 100W
- For tanks: 10 – 30Gal
- Temperature range: 68-90°F (20-32°C), adjustable
- Features: external controller
Unlike other glass aquarium heaters, this one comes with an external controller for convenient use. It offers a temperature range from 68°F to 90°F (20-32°C), which is easy to adjust with the dial on the controller.
This heater is suitable for both marine saltwater and freshwater. Its installation is as simple as positioning it horizontally or vertically with suction cups but ensure it is always submerged in the water while running. You should position it near the intake or output of your filter. Doing so helps to distribute heat more evenly.
The heater is designed for safety and durability. It’s made of heat-resistant milky quartz glass for shatter-proof and explosion-proof. The power cord is UL approved for electrical safety.
Overall, the Boxtech 100-watt aquarium heater is a reliable choice for your 20-gallon tank, and its service life can be three years or more.
Aqueon Pro submersible aquarium heater
- Wattage: 100 Watt
- For tanks: 20-30 Gal
- Temperature range: 68-88°F, ± 1°F, adjustable
- Features: LED light indicator
The Aqueon Pro submersible aquarium heater is known for its heavy-duty performance. It is shatter-proof and nearly indestructible, which is excellent in its ways and useful in many manners. It’s fully submersible and entirely safe for your aqua life.
It offers a temperature range from 68°F to 88°F for choice, with the accuracy of ± 1°F. At the top of the Aqueon aquarium heater, you can find a temperature adjustment knob and all you have to do is twist this to set the ideal temperature for your aquarium.
On the heater side, you can find an LED light indicator that helps you monitor the working status of the heater. It turns red while the heater is working and turns green if the tank’s water temperature reaches the set one and the heater temporarily stops heating.
Because it does not contain any LED display to show the current water temperature, you should use a digital thermometer (buy separately) to verify the temperature daily.