3 best heater for fish tank 20 gallon

Name: Uniclife 100 Watt Aquarium Heater with Thermometer, Fish Tanks Heater of 20 Gallon
Brand: Uniclife
Price: 13.99 USD
Availability: InStock
Rating: 4.6 (250 reviews)

A heater for a 20-gallon fish tank is an essential piece of equipment for maintaining a stable and suitable water temperature for your aquatic pets. Proper temperature regulation is crucial to ensure the health and well-being of your fish. Here's what you need to know about aquarium heaters for a 20-gallon tank:

Size and Wattage: When selecting a heater for your 20-gallon fish tank, it's important to choose the right size and wattage. A general guideline is to use a heater with a power rating of approximately 5 watts per gallon. So, for a 20-gallon tank, a 100-watt heater would be suitable. However, it's always a good idea to check the manufacturer's recommendations.
Submersible Heaters: Most aquarium heaters designed for small to medium-sized tanks are submersible, meaning they can be fully immersed in the water. These heaters are often compact and easy to install, with adjustable temperature settings.
Temperature Control: A good quality aquarium heater should have precise temperature control. Look for heaters with a thermostat that allows you to set and maintain the desired water temperature. Some heaters come with built-in thermometers to help you monitor the water temperature.
Safety Features: Safety is crucial when it comes to aquarium heaters. Many heaters have features like automatic shut-off in case of overheating, a protective casing to prevent fish from coming into direct contact with the heating element, and shatterproof glass to minimize the risk of damage.
Placement: It's important to place the heater correctly in your 20-gallon tank. Typically, you should install it near the water flow to ensure even heat distribution. Avoid placing it too close to the substrate or decorations, as this can cause temperature variations in different areas of the tank.
Heating Capacity: Ensure that the heater you choose has the capacity to raise and maintain the water temperature within the desired range for your specific fish species.Different types of fish have different temperature requirements.
Compatibility: Some heaters are designed for freshwater aquariums, while others are suitable for both freshwater and saltwater setups. Make sure to choose a heater that matches the type of aquarium you have.
Energy Efficiency: Look for heaters that are energy-efficient to help reduce your electricity consumption and save on utility costs over time.
Durability: Invest in a heater from a reputable manufacturer known for producing durable and long-lasting aquarium equipment. A reliable heater will ensure consistent temperature control for your fish.
Cost: The price of aquarium heaters can vary depending on their brand, features, and build quality. It's advisable to invest in a high-quality heater to avoid potential malfunctions or temperature fluctuations that could harm your fish.

In summary, selecting the right heater for your 20-gallon fish tank is crucial for maintaining a stable and comfortable environment for your aquatic pets. Proper temperature control contributes to the overall health and well-being of your fish and other aquatic inhabitants. Always follow the manufacturer's instructions for installation and operation to ensure the safety and effectiveness of your aquarium heater.

Below you can find our editor's choice of the best heater for fish tank 20 gallon on the market

Uniclife 100 Watt Aquarium Heater with Thermometer, Fish Tanks Heater of 20 Gallon

Uniclife

Based on 46 reviews Check latest price

Can be used in both freshwater and saltwater, applicable for 10~25 gallon fish tanks.
Adjust temperature by top red knob, range 68°F-93°F. Tube temperature displayed.
Water-tight of IP68 sealing. 2mm shatterproof quartz housing, bottom clash-proof cover. (NOTICE: Can’t be used even just cracked a tiny bit, pls contact us for replacement)
Measurement 9.7" x 1" (L x D). Only allowing for vertical or horizontal installment.
Package include aquarium heater x 1; Suction Cups x 3; stick-on thermometer x 1.

Product features

Uniclife 100W Aquarium Heater for 10- 25 Gallons

An aquarium heater is an essential device for warming water in your fish tank. HT-6100 Anti-Explosion Fish Tank Heater is suitable for up to 25 gallon aquariums, which can help your tropical fish and other aquatic pets to keep away from stress and disease by providing proper temperature. The heater will keep your tank at a constant temp especially in cold days. A good range for most fish is 76℉ to 80℉

Easy Adjustment

By rotating the Red knob at the top you can simply set the temperature from 68 - 93°F.
The red indicator light on while heating, automatic shut-off when reach the temp.

Submersible

The aquarium glass submersible heater must be fully immersed.
Install it either vertically or horizontally by attaching the suction cups to the glass of the tank.

Stick-on Thermometer

Distinguishable blue color shows the current temperature of your aquarium water.
Monitor and maintain a constant warm environment for your fish's health.

Mylivell Aquarium Heater Submersible Auto Thermostat Fish Tank Water Heater and Adjustable Temperature with Suction Cups

Mylivell

Based on 1 reviews Check latest price

High Quality: Aquarium heater made of high quality quartz glass, double seal material , advanced design, ensures safe operation.
Adjustable Temperature: The temperature of the fish tank heater can be adjusted automatically. Temperature setting range: 20°~34°C(65° F - 93° F), and the display is easy to read.
Fully Submersible. Power: 100W. Suggested water volume: 20 gal.
Both suiting for fresh or saltwater aquariums, provide a constant warm environment for your tropical fish to stay healthy.
Convenient and Safe: Our aquarium heater thermostat has two suction cups for attachment to the fish tank. The polarized plug prevents electrical shock.

User questions & answers

Question:	does it turn off when it is at the chosen temperature
Answer:	Firstly,you need to set the temperature.If you set at 78,if the water in the tank is lower than the setting,the heater will be heated, the red light is on. After heating,the water in the tank up to the temperature of the setting,the heater won’t heat up, the red light is off. So don't worry about the light shock. If there is any problem,feel free to contact me .
Question:	Is the black plastic bumper at the bottom supposed to stay on when using heater or is it supposed to be remover before turning heater on
Answer:	I think its supposed to stay on
Question:	Can i use this on a circular aquarium? Will the suction cups hold to a circular tank
Answer:	I don't see any issue of mounting this unit in a circular shaped tank. One major issue is to make sure that the unit is totally submerged preventing it from burning out. There is a line on it stating it must be below water. Do this... and it will last.
Question:	What is the actual length of the 50W heater itself, not the cord
Answer:	The aquarium heater 50W is about 9.5 inch long.Hope this helps you.

Product features

Mylivell Submersible Aquarium Heater

You will need an aquarium heater to keep your tank in a steady and controlled temperature, as proper temperature range is very important to fish and other Aquatic in winter.
Mylivell Submersible Aquarium Heaters are one of the most popular way to keep your tank at a steady and controlled temperature, Fish water heater will be your best choice!

FREESEA 25/50/100/200/300 Watt Aquarium Heater with Aquarium Submersible Thermometer

FREESEA

Based on 3 reviews Check latest price

★【25 Watt Heater】： This Aquarium heater is suitable for 1 to 5 gallons aquariums, Length - 6.8 inch,voltage 110-120V, power cord is 4.0 ft, please choose the right wattage aquarium heater according to our size chart.
★【Temperature range】: 63°F~95°F , 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.
★【Intelligent temperature control】： Automatic constant temperature function, when water temperature reaches to specified temperature value, heater will automatically stop heating, when water temperature is lower than the set temperature, heater will automatically start heating. Furthermore, Automatic safety shut-off feature, and overheating protection.
★【Note】: 1. Aquarium heater is 100% submersible use only, during its heating time, heater must be 100% submerged into the water.,Please unplug the power supply when cleaning the fish tank or aquarium water changes. 2. Heater rod is suitable for people over 16 years of age. Children or minors should be under adult guidance or supervision.
★【SATISFACTION GUARANTEED】： Gain the confidence to go hard with us! Our Aquarium Heater is built with durability in mind and safety for every design, In the remote possibility that you’re not satisfied with our product, just contact us, and we will gladly give you a new Aquarium Heater replacement. 12 Month Warranty and 24 Hour Professional After-sales Service.

User questions & answers

Question:	Can I use a short extension cord with this 25 watt heater because the port is so short
Answer:	All of my fish tank items are connected to a surge protected extension cord. This heater is one of the items plugged into it.
Question:	Does this heater come with suction cups
Answer:	Yes
Question:	Are their any directions to put the heater in
Answer:	They have directions right on the side of the box when it ships. Pretty much the heater has to be fully submerged
Question:	Has anyone else experienced condensation in the display? it makes it very hard to read. does anyone know how i can stop this from happening
Answer:	Move the display further from the aquarium

Product features

FREESEA Aquarium Submersible Heater

1.Temperature range: 63°F~95°F , It is very easy to adjust the temperature you need.
2.Automatic constant temperature function, when water temperature reaches to specified temperature value, heater will automatically stop heating, when water temperature is lower than the set temperature, heater will automatically start heating.