The Best Aquarium Heaters, According to a Pet Fish Veterinarian

Best Overall

Orlushy Submersible Aquarium Heater

$26 $23 at Amazon $17 at Walmart

The Orlushy Submersible Aquarium Heater provides any fish keeper with a reliable heater with a solid outer casing and full adjustability. This product line comes in a variety of sizes, accommodating 1 to 6 gallons with the 25-watt heater and up to 75 gallons with the 500-watt heater. Two suction cups keep your heater secured and away from the main area of your tank, and a digital thermometer ensures your heater is working correctly.

What we appreciate about this model is its ease of use and clear functions. Its size variety makes it very friendly for most pet fish tank sizes while keeping a good price point. Overall, the Orlushy Submersible Aquarium Heater is a great choice for your aquarium, no matter what tropical species you have or the size of their tank.

_{Temperature Range: 68 to 89 degrees | Gallon Range: 1 to 75 gallons | Wattage: 25, 50, 100, 150, 200, 300, 500 | Cord Length: 6 feet}

Best for Large Tanks

Fluval E Electronic Heater

$69 $35 at Amazon $45 at Chewy

If you have a lot of water to heat, then you need the Fluval E300 Advanced Electronic Heater. This 300-watt heater can heat up to 100 gallons of water to 69 to 93 degrees Fahrenheit. Designed specifically for larger tanks, this heater has an easy-to-read digital display with corresponding color codes to ensure your water temperature is within the proper range.

The unit is fully submersible with a protective outer shell to keep fish and invertebrates from getting too close. Yes, it is the most expensive heater on this list, but a lot of technology goes into a heater designed to keep a large volume of water heated consistently.

_{Temperature Range: 68 to 93 degrees | Gallon Range: 75 to 100 gallons | Wattage: 300 | Cord Length: 6 feet}

Best for Small Tanks

HITOP Adjustable Aquarium Heater

$12 at Amazon

Small tanks are the hardest to heat consistently, but the HITOP Adjustable Aquarium Heater has taken this into account with even its smallest model. The 25-watt model is easy to set up and fully adjustable to your fish’s preferred temperature.

If you need something a little bit bigger, there is a full range of sizes for your smaller aquariums. Very easy to install and use, the HITOP Adjustable Aquarium heater is a good choice for smaller aquariums.

_{Temperature Range: 68 to 93 degrees | Gallon Range: 5 to 10 gallons | Wattage: 25 | Cord Length: 4.9 feet}

Best Nano

FREESEA Fish Tank Submersible Heater

$19 at Amazon

Fish keepers with small, nano tanks requiring heat should check out the Freesea 50W Mini Aquarium Heater. Unlike most tube-shaped heaters, this flat disk takes up less of your valuable tank space and can provide quite a bit of heat for a small space. This model comes with an external adjustable temperature range and has an easy-to-read digital display.

Larger models are available if you plan on upgrading your tank from nano to medium.

_{Temperature Range: 59 to 93 degrees | Gallon Range: 1 to 10 gallons | Wattage: 50 | Cord Length: 3.5 feet}

Best Budget

Tetra HT Submersible Aquarium Heater

$20 $14 at Amazon $10 at Chewy $17 at Walmart

The Tetra Submersible Aquarium Heater is a line of heaters that are very inexpensive, but also do not have many features, such as adjustable temperature settings, and only come with one suction cup attachment. However, if you need a heater and have a small budget, this heater will reliably keep your fish at a comfortable temperature.

_{Temperature Range: 78 degrees | Gallon Range: 2 to 10 gallons | Wattage: 100 | Cord Length: 6 feet}

Best Heater Guard

Tnfeeon Fish Tank Heater Protective Case

$12 at Amazon

If you have to protect your fish or invertebrates from your heating element, then consider the Tnfeeon Fish Tank Heater Protective Case. What is great about this heater case is that you can customize the length to almost any standard heater brand or model. This is a great addition to heaters that won’t stay put and need some extra stability or have unruly tankmates.

It includes six sections to accommodate 25-to-1000-watt heaters and two strong suction cups for solid attachments.

_{Temperature Range: Not applicable | Gallon Range: Not applicable | Wattage: Accommodates 25-to-1000-watt heaters | Cord Length: Not applicable}

Best Preset

Aqueon Preset Aquarium Heater

View on Amazon View on Chewy $24 at Walmart

The Aqueon Preset Heater is a straightforward choice if you are not able to consistently monitor the water temperature in your tank. The heater is constructed with durable quartz glass to resist shattering, and its compact design allows for the device to be placed vertically or horizontally with suction cups included.

There is an LED indicator light that displays red when actively heating. The automatic shutoff ensures that the water in your tank won't overheat. While this product does come in different wattages to accommodate a range of tank sizes, the Preset Heaters from Aqueon are more consistent with lower-capacity tanks.

_{Temperature Range: 78 | Gallon Range: 5 to 75 gallons | Wattage: 50, 100, 150, 200 | Cord Length: Not listed}