Before setting up a fish tank, you’ll want to buy the best aquarium heater you can find. A fish tank heater is an essential piece of equipment to keep your fish healthy and thriving.
Are you not sure where to start? There are so many types of heaters and brands to choose from, and the choices can be intimidating.
To narrow down your options, I’ve created a list of the five best aquarium heaters on the market today. Whether your aquarium is big or small, these fish tank heaters are here to help.
Why Do You Need An Aquarium Heater?
Maintaining a warm and stable fish tank temperature is essential to the health of your tropical fish. So, if you plan to keep a tropical fish tank, then a good heater is a necessary piece of equipment to have before adding your fish to the tank.
Your tropical fish tank temperature should generally sit between 75-80°F (25-27°C). Tropical fish do best at these temperatures and will stay happier and healthier.
Aqueon explains why it’s bad for a tropical fish’s health to live in water too cold:
“Fish are cold-blooded – aka ectothermic or poikilothermic – animals, meaning they cannot control their body temperature. Instead, they rely on the temperature of their environment to regulate their metabolisms and activity levels. When it’s too cold, they’re less active, their appetite is reduced and their immune systems are compromised, making them more susceptible to disease.”
Why Are Submersible Heaters So Popular?
Submersible water heaters are suitable for people who don’t like to see their heaters. Because the entire heater can go in the water, they are easy to hide behind decorations. Submersible heaters are often more efficient and less likely to experience damage.
5 Best Aquarium Heaters
What makes these aquarium heaters the best? To pick the best heaters, I studied reviews from actual users and compared heating capacity, cost, and durability.
1. Finnex HMS Digital Titanium Aquarium Heater — Best Aquarium Heater Overall
For the best of the best, I recommend choosing the Finnex HMS Digital Titanium Aquarium Heater. The Finnex HMS is the best fish tank heater because it has the most features, durability, and versatility.
The Finnex HMS has the best heating capacity, with 50W options for smaller and 500W for larger tanks.
With advanced digital controls, the Finnex HMS reads temperature instantly with an accuracy of 0.5°F. The digital controls outside the tank make for quick and easy temperature adjustments.
PROS:
- 3-Digit Display & Control
- 1/10th Degree Calibration Capable Heater
- Unbreakable Titanium Tube
- Corrosion-Resistant
CONS:
- Short Cables
- Temperature Sensor is Large
The Finnex HMS has the most advanced technology and safety features, making it the best heater overall.
| Heater Capacity | Durability | Adjustable OR Pre-Set Temperature | Cost | |
| Fluval Advanced Electronic Heater | 50W, 100W, 200W, or 300W | Integrated Fish Guard & Safety Shut-Off | Adjustable | $55.99-$68.99 |
| Aqueon Heater Pro Series | 50W, 100W, 150W, 200W, 300W | Auto-Shut Off & Shatterproof | Adjustable | $44.99-$54.99 |
| Finnex HMS Digital Titanium Aquarium Heater | 50W, 100W, 150W, 200W, 300W, 500W | Corrosion-Resistant Titanium &Heater Guard | Adjustable | $56.43-66.75 |
| Aquatop QPH Quartz Platinum Heater | 50W, 100W, 200W, 300W, & 400W | Shatter- Resistant Quartz Platinum Glass & Shield | Adjustable | $19.99-39.99 |
| Fluval M-Series Submersible Heater | 50W, 100W, 150W, 200W, or 300W | Shock & Heat- Resistant Borosilicate Glass | Adjustable | $18.00-$35.99 |
5 of the Overall Best Submersible Aquarium Heaters
2. Aquatop Submersible Heater — Best Aquarium Heater For Mini Tanks (Under 10 Gallons)
The Aquatop submersible water heater is the best for mini aquariums under 10 gallons.
The Aquatop submersible fish tank water heater has the heating capacity to heat up to 13 gallons, far more than the other heaters made for mini aquariums.
It is a small fish tank heater, but it’s adjustable, affordable, and durable.
PROS:
- Safe for Freshwater & Saltwater Use
- Easy Installation with Suction Cups
- Visible & Adjustable Temperature Settings
- Double Insulation & Insulated Glass
CONS:
- Finicky Temperature Adjustment Knob
- Larger Size
| Heater Capacity | Durability | Adjustable OR Pre-Set Temperature | Cost | |
| Aqueon Mini Aquarium Heater | Up to 5 gallons (10 watts) | Shatterproof & Thermal Safety Shut-Off | Pre-Set | $23.00 |
| Marina Submersible Aquarium Heater | Up to 1.5 gallons (8W) | Durable Polymer | Pre-Set | $12.52 |
| Aquatop Submersible Heater | Up to 13 gallons (50W) | Overwind Protection & Insulated Glass | Adjustable | $11.99 |
| Cobalt Aquatics Neo-Therm Heater | Up to 6 gallons (25W) | Thermal Protection & Shatterproof Outer Casing | Adjustable | $53.13 |
| Hydor Theo Aquarium Heater | Up to 6 gallons (25W) | Shatterproof & Shock-Resistant | Adjustable | $19.31 |
5 of the Best Submersible Aquarium Heaters For Mini Aquariums
3. Fluval M-Series Submersible Heater — Best Aquarium Heater For Small Tanks (Under 55 Gallons)
The Fluval M-Series submersible heater is an excellent choice for small aquariums under 55 gallons. These heaters come with a durable shock-resistant borosilicate glass design that reflects light and blends in with its surroundings.
PROS:
- Built-In Reflective Technology
- Computer-Calibrated Thermostat
- Easy-to-Adjust Temperature Control
- Shock-Resistant Borosilicate Glass
- Suitable for Freshwater & Saltwater
CONS:
- Larger Size
- No Plastic Guard at the Bottom For Protection
| Heater Capacity | Durability | Adjustable OR Pre-Set Temperature | Cost | |
| Eheim Jager Aquarium Heater | 25W, 50W, 75W, 100W, 125W, 150W, or 200W | Double-Insulated Safety Cable & Double-Sealed Tube | Adjustable | $25.90-33.99 |
| Aquatop Submersible Heater | 75W, 100W, 150W, or 200W | Overwind Protection & Insulated Glass | Adjustable | $26.75-$31.99 |
| Tetra Submersible Heater | 50W, 100W, 150W, or 200W | Shock-Resistant | Pre-Set | $11.99-28.99 |
| Marineland Precision Submersible Heater | 75W, 100W, 150W, or 200W | Automatic Shut-Off & Mica Core | Adjustable | $16.30-23.30 |
| Fluval M-Series Submersible Heater | 50W, 100W, 150W, or 200W | Shock & Heat- Resistant Borosilicate Glass | Adjustable | $18.00-35.99 |
5 of the Best Submersible Aquarium Heaters For Small Aquariums (<55 Gallons)
4. Marineland Precision Submersible Heater — Best Aquarium Heater For Large Tanks (Over 55 Gallons)
The Marineland Precision submersible heater is the best fish tank heater for larger aquariums over 55 gallons. The heater offers several heating capacities from 250W to 400W.
The temperature adjustment knob is easy to manipulate and understand as the device clicks every time you adjust it up or down by 1°F. The temperature display glows red for easy viewing and temperature reading.
These heaters are durable, with mica cores surrounded by a flattened mesh heating element for extra protection and heat transference.
PROS:
- Suitable for Both Freshwater & Saltwater
- Easy Temperature Adjustment
- Durable & Efficient Heating Design
- Safety Switch to Prevent Overheating
- Easy-to-Use Mounting Brackets & Suction Cups
CONS:
- Larger Size
- Temperature Reading Light is Very Bright at Night
- Temperature Numbers on Heater Sit at Random Intervals
| Heater Capacity | Durability | Adjustable OR Pre-Set Temperature | Cost | |
| Eheim Jager Aquarium Heater | 250W or 300W | Double-Insulated Safety Cable & Double-Sealed Tube | Adjustable | $34.39-37.99 |
| Marineland Precision Submersible Heater | 250W, 300W, or 400W | Automatic Shut-Off & Mica Core | Adjustable | $25.66-53.20 |
| Aquatop Submersible Heater | 250W, 300W | Overwind Protection & Insulated Glass | Adjustable | $35.79-37.99 |
| Fluval M-Series Submersible Heater | 300W | Shock & Heat- Resistant Borosilicate Glass | Adjustable | $35.99 |
| Finnex HMS Digital Titanium Aquarium Heater | 300W, 500W | Corrosion-Resistant Titanium &Heater Guard | Adjustable | $67.61-66.75 |
5 of the Best Submersible Aquarium Heaters For Large Aquariums (>55 Gallons)
5. Fluval M-Series Submersible Heater — Best Aquarium Heater For Those On A Budget
The Fluval M-Series submersible aquarium water heater is the best choice if you’re looking for an aquarium heater on a budget. They offer a variety of heating capacities from 50W for the smallest tanks to 300W for larger tanks, and all heater sizes are affordable.
PROS:
- Built-In Reflective Technology
- Computer-Calibrated Thermostat
- Easy-to-Adjust Temperature Control
- Shock-Resistant Borosilicate Glass
- Suitable for Freshwater & Saltwater
CONS:
- Larger Size
- No Plastic Guard at the Bottom For Protection
| Heater Capacity | Durability | Adjustable OR Pre-Set Temperature | Cost | |
| Fluval M-Series Submersible Heater | 50W, 100W, 150W, 200W, or 300W | Shock & Heat- Resistant Borosilicate Glass | Adjustable | $18.00-$35.99 |
| Marineland Precision Submersible Heater | 75W, 100W, 150W, 200W, 250W, 300W, or 400W | Automatic Shut-Off & Mica Core | Adjustable | $16.30-53.20 |
The 2 Best Aquarium Heaters For Those On A Budget
Are Aquarium Heaters Dangerous?
There isn’t much to worry about when it comes to aquarium heater safety. Aquarium heaters come with safety in mind; you can leave them on 24/7. Most modern heaters include safety features, including “automatic shut-off” to prevent the heater from overheating.
Just because aquarium heaters and other aquarium equipment are designed to be safe doesn’t mean you can be careless with your equipment. Aquariums are a common cause of house fires. However, aquarium heaters aren’t the cause; power strips are the culprit.
FOX43 News explains how aquariums cause fires when you misuse them:
“Detective Hopple showed FOX43 Reveals how a tank full of water can be a serious fire hazard if you do not have what is known as a “drip loop.” The “drip loop” is the part of the power supply cord below the level of the wall electrical outlet. He said aquariums should never be plugged into a power strip that is lying flat on the floor.
“Where they plug into the wall, they should always have a drip loop,” explained Det. Hopple. “The drip loop basically is so that if water does come down, it can’t travel back up and it plugs into the wall. That way, if any water would get on there, it would drop onto the floor and not get into the electrical outlet.”
When water does get into the outlet, it causes corrosion, resistance, and overheating.”
Conclusion
Consider the Finnex HMS Digital Titanium Aquarium Heater if you’re looking for the best tank heater for your fish. The Finnex HMS heater is one of the best and safest on the market, with the most comprehensive capabilities and the latest technology.
Prefer one of the other heaters on this list? That’s okay, too. These are the best aquarium heaters whether you have a small or large tank, are on a budget, or want the best heater money can buy. Rest assured that your fish will be warm and safe, whichever heater you choose.
FAQs
Cold-water species don’t need a heater, but with tropical species, a heater is necessary. Tropical fish species do best in temperatures between 75-80°F (25-27°C). Without a heater, your tank’s water is unlikely to reach these temperatures.
People who live in hot climates can sometimes get away without using a heater, but in most cases, it’s still a good idea to have one. Cold spells happen, and heaters ensure your water stays at a healthy temperature.
Plus, your aquarium’s water fluctuates with the temperature, even if your climate is generally hot. Temperature fluctuations can be stressful for fish. A heater ensures a consistent temperature that is better for your fish’s health.
Aquarium heaters, and aquarium equipment in general, do not use much electricity. The larger your aquarium and equipment, the more electricity you’ll use, but even 100-gallon aquariums don’t use much energy.
Some estimates say that, for the average aquarium (under 55 gallons), a heater will cost you about 20 cents a day to run. For larger aquariums, that estimate may go up to half a dollar.
