Fluval Submersible Glass Aquarium Heater, 50-watt

By Fluval
Rated 3.7222 out of 5 stars
$34.99Chewy Price

Spend $100, Get $30 eGift Card with code: FALL

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This Item – Fluval Submersible Glass Aquarium Heater, 50-watt
Rated 3.7222 out of 5 stars
$34.99Chewy Price

Spend $100, Get $30 eGift Card with code: FALL

Fluval Flex Aquarium Kit, White, 15-gal
Rated 2.6 out of 5 stars
$132.95Chewy Price

Spend $100, Get $30 eGift Card with code: FALL

Fluval Spec Aquarium Kit, 5-gal
Rated 3.9767 out of 5 stars
$115.57Chewy Price

Spend $100, Get $30 eGift Card with code: FALL

Total Price: $283.51

About This Item


  • Sleek and compact submersible heater provides exceptional performance and unsurpassed reliability.
  • High-density ceramic heating element is encased in shock-resistant borosilicate glass.
  • Temperature can be set between 68 and 86 degrees F; suitable for up to 15-gallon fresh or saltwater tanks.
  • Unique reflective technology of the outer casing makes the heater virtually invisible in your tank.
  • The included dual suction cups allow you to easily install the heater inside your aquarium.

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Fish TypeBetta, Cichlid, Goldfish, Marine Fish, Tropical FreshwaterMarine Fish, Tropical FreshwaterMarine Fish, Tropical FreshwaterMarine Fish, Tropical FreshwaterTropical Freshwater
Aquarium TypeSaltwater, FreshwaterSaltwater, FreshwaterSaltwater, FreshwaterSaltwater, FreshwaterFreshwater

Questions & Answers

16 Customer Questions

Cannot choose the size
Answer by mossbackApr 29, 2022
3-5 watts per gallon.

Does this shut off to maintain the desired set temperature?
Answer by ChewySep 17, 2018
The unit heats only when the pilot light is illuminated. When the pre-selected temperature is reached, the pilot light shuts off. It will light again only when the heater is required to maintain the temperature at the selected level.

Is this the heater I need for a 5 gallon tank. If not what do your recommend please
Answer by ChewyAug 12, 2020
The Fluval Submersible Glass Aquarium Heater is suitable for your tank, it is designed to work in tanks up to 15-gallon (fresh or saltwater tanks).

Can this be used in an acrylic fish tank?
Answer by ChewyOct 08, 2018
This heater is safe to use on any tank that can withstand temperatures up to 86 degrees Fahrenheit.

ReviewsWrite a Review

Rated 3.7222 out of 5 stars
36 Ratings
Would recommend to a friend

35 Customer Reviews

Rated 4 out of 5 stars
By Rick on Apr 7, 2023
Top 1000 Contibutor

Not great, but ok.

I have several Aqua Top heaters, but I had a 50-watt heater that developed a tendency to not shut off. I like Fluval products so bought the 50-watt heater to replace the Aqua Top. The Fluval keeps the water temperature constant, but the temperature does not correspond to the dial setting. The silver color looks nice, but its more noticeable than clear glass. It has a "cool blue" on indicator light but it's so dim that it's hard to see when the aquarium light is on. The heater seems to be ok, but I'm not overly impressed.

Rated 5 out of 5 stars
By izero on Feb 3, 2023

Too Tall for A Dennerle Ten Gallon Tank

The top sticks out so the lid can't be placed on the tank so I'm returning this Otherwise, it looks well made durable. I'd keep it if I had plans for a larger tank. My advice is to check your height and lid placement. It says up to 15 gallons but that is relative to your tank.

Rated 5 out of 5 stars
By Dave on May 14, 2023

Great product, very accurate

Rated 1 out of 5 stars
By AmyM72 on Jul 23, 2022

So disappointing

I bought this heater for my 29 gallon setup. It had been recommended to me by several people, so I splurged on it. So disappointing! I'd keep turning the temp up and my tank never went above 72. I even adjusted the dial as high as it would go and the temp stayed at 75. Don't waste your money on this heater!

Rated 5 out of 5 stars
By ChihuahuaLover on Dec 11, 2022

Great Value

Works as described. I am buying another for my second aquarium.

Rated 5 out of 5 stars
By MerleTheGirl on Apr 5, 2022

Excellent purchase

The best aquarium heater I have purchased. Extremely accurate and the appearance in the aquarium is elegant. In fact, I am purchasing another one to replace a different heater that I purchased that is NOT heating the aquarium sufficiently.

Rated 3 out of 5 stars
By ehhnot on May 29, 2022

stopped working

ive had this for two months now and it just up and stopped working on me. could i get a recommendation on a new one?

Rated 1 out of 5 stars
By FishMom on Feb 19, 2022

Too big for 5gallon

This is too tall for my tank. I have the 5 gallon Aqua Culture starter kit and it’s much too tall for my tanks water level. I’m sure it would work fine for a taller tank. Definitely going to try to return.

Rated 5 out of 5 stars
By Nano5 on Dec 20, 2021

Great Heater

Pretty nice heater. I was sceptical about the glass cover but it does look nicer I think than plain black. The picture does not do it justice. I have it in a 5 gallon nano so no, it does not fit in the filter area if you keep the sponge. But it is fully submersible so you can put it like mine in the tank. The downsize is it is visible, the upside is it has no issue at all keeping temp. The smaller size ones might

Rated 3 out of 5 stars
By talm on Feb 3, 2022

very noticable

This heater works OK. I have the white Edge tank so the silver and black on this heater make it very noticable, and due to it's large size, it's hard to hide. The best way to hide something is to make it blend in. This does not.