Our Top Picks
Best Overall: Aqueon Pro Submersible 100W Heater at Amazon
"Has durable, non-corrosive construction and even heat distribution."
Best Budget: Tetra HT Submersible Aquarium Heater at Amazon
"This little heater holds up to extended use despite its slim price tag."
Best for Betta Fish: hygger Submersible Fish Tank Heater at Amazon
"Can be used in saltwater and freshwater tanks."
Best for Turtles: TetraFauna Aquatic Reptile Heater at Amazon
"Two oversized suction cups ensure it’ll stay in place even if it’s jostled."
Best Electronic: Fluval E 100-Watt Electronic Heater at Amazon
"Has an LCD display that gives you an instant reading of your water temperature."
"Designed for years of continuous use thanks to the quality materials."
Best for Plants: Hydor Hydrokable Substrate Heate at Amazon
"Circulates heat through the bottom of your tank to help plants thrive."
Best In-Line Heater: ISTA In-Line External Heater at Amazon
"Easy to install and highly efficient."
01 of 08
Best Overall: Aqueon Pro Submersible 100W Heater
While there’s no shortage of specialized heaters, sometimes all you need is a great all-around product that gets the job done, does it well and won’t wreck your budget in the process. The Aqueon Pro Submersible 100W Heater is solid through and through, with durable, non-corrosive construction and even heat distribution. The heater has a range of 68 to 88° F and is accurate within one degree of the desired temperature. It’s fully submersible, can be used in fresh or saltwater tanks and automatically shuts off and resets in the event of overheating.
Customers say that the Aqueon Pro Submersible 100W Heater is visually unobtrusive and reliably keeps a level temperature in their tank. With its combination of a simple setup and quality construction (some buyers have gotten years out of it), it’s a great choice for newbies and experienced aquarists alike.
02 of 08
Best Budget: Tetra HT Submersible Aquarium Heater With Electronic Thermostat
If you’re just starting out and focusing on the other end of the cost spectrum, there’s still no shortage of great, reliable heaters that will keep you and your fish happy. This one from Tetra comes in at a budget-friendly $6.99—and while it’s relatively bare bones, it gets the job done. The heater will keep your water at a steady 78° F, the optimum temperature for most tropical fish, with no adjustment or fiddling with controllers required. Meanwhile, an LED light switches from red to green to let you know when the water’s been fully warmed. It’s also fully submersible, with an unobtrusive footprint, and available in both 50 and 100-watt models.
According to online customers, this little heater holds up to extended use despite its slim price tag. While you may notice some slight fluctuations in temperature, it stays within the recommended scale (check with your own thermometer occasionally to confirm).
03 of 08
Best for Betta Fish: hygger Submersible Fish Tank Heater
With bright coloring and flamboyant fins, betta fish are a popular choice for countless aquarium owners. But since they’re used to a tropical environment, you’ll need to set your tank at the appropriate temperature. The hygger Submersible Fish Tank Heater can be adjusted using a controller that hangs outside the tank, with a temperature range of 75 to 91° F. Its distinctive milky-white quartz construction can last up to three years in freshwater (but can be used in saltwater tanks as well), and is reliably shatterproof even at high temperatures. An LED light indicates when the tank is fully heated.
The hygger Submersible Fish Tank Heater can be purchased in sizes appropriate for 30-60 gallon tanks, and customers call it a “functional piece of art” thanks to its uniquely eye-catching look. The ability to adjust the temperature without sticking your hand in the tank is also called out as a definite plus. All told, it’s a smart buy for betta owners who need to keep their water’s temperature in the tropical sweet spot.
04 of 08
Best for Turtles: TetraFauna Aquatic Reptile Heater For Frogs, Newts & Turtles
As you’d expect, what works for fish doesn’t necessarily work for other, larger animals—like turtles. You’ll want a heater that’s sturdier than your average one and less likely to be jarred by movement, and the TetraFauna Aquatic Reptile Heater is a great option. Two oversized suction cups ensure it’ll stay in place even if it takes a full-on hit from one of your reptile friends, while a protective plastic cage keeps it safe from harm. The 100w heater is fully submersible and specifically designed for reptile aquariums, keeping your tank at an optimal 78° F.
According to customers, this heater is a “turtle favorite,” writing that it keeps the temperature exactly where it needs to be. The protective cover also ensures your turtles won’t accidentally burn themselves if they come into contact with it.Continue to 5 of 8 below.
05 of 08
Best Electronic: Fluval E 100-Watt Electronic Heater
While countless heaters purport to keep your tank’s water at a steady temperature, you’ll often need to test it with a second thermometer to confirm your device is working properly. Not so with the Fluval E 100-Watt Electronic Heater, which has an LCD display that gives you an instant reading of your water temperature. The reader can be toggled between Fahrenheit and Celsius and relies on two sensors to provide a high level of accuracy. It will also change color to reflect a shift in temperature, but the heater should keep the tank within two degrees of what’s been selected. For larger tanks, the heater is also available in 200 and 300-watt models.
Customers say the Fluval E 100-Watt Electronic Heater is well designed, with a sleek profile that blends in with the tank, while the digital temperature reader is spot-on—and it couldn’t be easier to give it a quick check as you walk by.
06 of 08
Best Titanium: Finnex Electronic Controller Aquarium Titanium Tube with Heater Guard
For the serious aquarist, a titanium heater is designed for years of continuous use thanks to quality materials that are virtually indestructible. The Finnex Electronic Controller Aquarium Titanium Tube with Heater Guard is highly corrosion-resistant and will hold up for years in both fresh and saltwater tanks. Titanium also heats up more quickly than other materials, rapidly giving you precise temperature within two degrees of what’s been selected (the controller hangs outside the tank).
The Finnex heater comes in a range of models with varying levels of electrical power—from 50 watts on up to 500, depending on the size of your tank. Customers write that it has absolutely stellar build quality—letting them rest assured it will never crack like a typical glass tube or (gasp!) electrocute their fish.
07 of 08
Best for Plants: Hydor 75w Hydrokable Substrate Heater
If you’re the owner of a heavily planted tank, a standard submersible heater might not be ideal when it comes to keeping your plants fresh and vibrant. Instead, consider a heater like this one from Hydor, which takes the form of an insulated cable that goes beneath your tank’s substrate. Like other heaters, it’s fully submersible (although it also works in dry settings), but it circulates heat through the materials at the bottom of your tank—an effect that helps both plants and fish thrive. Suction cups positioned along the length of the cable help ensure the perfect fit and positioning inside your tank, while double-silicone insulation ensures it’s just as safe as a convention aquarium heater.
Customers write that the Hydor substrate heater is a great option for planted tanks, and have used it for years with no issue. Just bear in mind that its max temperature is 78 degrees, and you might want to buy a few extra suction cups for help during setup. But once your substrate’s been placed over the heater, the accumulated weight holds it in place just as well.
08 of 08
Best In-Line Heater: ISTA 150w/300w/500w In-Line External Heater
Want to save some space inside your tank and dedicate more room for fish and less for hardware? Consider an in-line heater, which warms up the water in your tank from the outside via an attachment to its filtration system. This one from ISTA is easy to install and highly efficient, thanks to its thermal glass design. Temperature can be set with the push of a button (an LCD shows the current temperature inside the tank), while sensors detect the warmth of the water flowing in and out for a high degree of accuracy. It’s available in six different models for various tank sizes and can be used with both fresh and saltwater tanks.
The ISTA in-line heater is incredibly consistent, customers write, and is truly a “set and forget” heater that won’t corrode or break over time. One note: The device’s LED only offers Celsius temperature readings, but a quick Google search should be an easy solution for U.S. customers. All told, it’s worth the slightly higher price tag to keep the heater outside the tank and leave more room for the seascape you’ve taken great care to maintain.