Fluval M 300Watt Submersible Fish Heater

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$38.99 (-3%) Chewy Price
$39.99 List Price
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Pay in 4 interest-free payments of $9.75. .

About This Item

Details

  • Quality heater made in Europe with quality components.
  • Sleek and compact design.
  • Submersible heater delivers excellent performance and reliability.
  • Mirror technology reflects the colors of the aquarium to enhance its appearance.
  • For fresh and saltwater tanks.

Instructions

Frequently bought together

Questions & Answers

1 Customer Questions

For what size tank

Answer by Chewy • Nov 02, 2025
The 300-Watt heater is designed for aquariums up to 80 US Gal / 202 L.
Reviews
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4.2
Rated 4.2 out of 5 stars
30 Ratings
Terms & Conditions

9 Customer Reviews

Rated 1 out of 5 stars
By Brian on Nov 22, 2025

Not good

Will not heat up my tank More than 74 degrees. Waste of money

Will not heat up my tank More than 74 degrees. Waste of money

Rated 5 out of 5 stars
By Jamie on May 13, 2025

Works great

Works great stays at temp keep set to degree never issue our 2 love them when other goes out I will replace with this one, it will be the go to for all heaters

Works great stays at temp keep set to degree never issue our 2 love them when other goes out I will replace with this one, it will be the go to for all heaters

Rated 3 out of 5 stars
By Ronnie on Mar 18, 2025

Shipping

I order heater last week came not bubble wrap heater not working. Reported it they ship another 1 came today not bubble wrap. I hope this works Customer service

I order heater last week came not bubble wrap heater not working. Reported it they ship another 1 came today not bubble wrap. I hope this works Customer service is excellent. People in shipping need to be fire.

Rated 2 out of 5 stars
By Catherine on Sep 22, 2024

Doesn't work

Only giving 2 stars instead of 1 due to fluval's good customer service. This thermometer will not warm my 80g tank. At first I thought I received a faulty thermometer

Only giving 2 stars instead of 1 due to fluval's good customer service. This thermometer will not warm my 80g tank. At first I thought I received a faulty thermometer and fluval sent me new one. Still doesn't work. My water stays around ambient temperature despite the the thermometer being set at several degrees above.

Rated 5 out of 5 stars
By Heather on Dec 27, 2024

Plug and play

Set the temp, drop into water, plug in and walked away! Came back 1 hour later, water was perfect temp

Set the temp, drop into water, plug in and walked away! Came back 1 hour later, water was perfect temp

Rated 1 out of 5 stars
By SeeLee on Dec 9, 2024

Shipping

Heater wasn't bubble wrapped it bounced around everywhere I'm lucky it still works

Heater wasn't bubble wrapped it bounced around everywhere I'm lucky it still works

Rated 5 out of 5 stars
By Debra on Jan 31, 2025

Excellent!

Heated tank as expected.

Heated tank as expected.

Rated 5 out of 5 stars
By Kera on Dec 25, 2023

Great Product

I recently purchased the Fluval M 300Watt Submersible Fish Heater for my 75 gallon aquarium and I am extremely satisfied with its performance. First and foremost,

I recently purchased the Fluval M 300Watt Submersible Fish Heater for my 75 gallon aquarium and I am extremely satisfied with its performance. First and foremost, the heater is very easy to install. It comes with detailed instructions that are straightforward to follow, and within minutes, I had it up and running in my tank. The adjustable temperature settings are also a great feature, allowing me to set the perfect temperature for my fish. The heater maintains a consistent temperature throughout the tank, which is crucial for the health and well-being of my fish. I have noticed a significant improvement in their activity levels and overall behavior since using this heater. Additionally, the Fluval M 300Watt Submersible Fish Heater is very durable and well-built. It feels sturdy and reliable, and I have no doubts about its longevity. The compact design is also a plus, as it doesn't take up much space in my tank. Lastly, the heater operates silently, which is a huge bonus for me. I have had heaters in the past that were quite noisy, and it was quite annoying. With this Fluval heater, I can enjoy the peaceful ambiance of my aquarium without any distractions. Overall, I highly recommend the Fluval M 300Watt Submersible Fish Heater. It is a high-quality product that is easy to install, maintains a consistent temperature, and operates silently. My fish are happy and healthy, and that's all I could ask for.

Rated 5 out of 5 stars
By Michael on Sep 10, 2024

Made well and easy to set

Fast shipping

Fast shipping