Fluval Underwater Filter Poly/Carbon Cartridge, 2 count

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About This Item

Details

  • Helps eliminate harmful contaminants and keeps your fish safe.
  • One side features a polyester filter pad that removes fine debris and contaminants.
  • The other side contains carbon to remove dangerous contaminants along with unwelcome colorants and odors.
  • Specifically designed for use in the Fluval Underwater Filter for Aquariums, Size U4.
  • Ships in a pack of two cartridges; suitable for use in freshwater, marine or reptile environments.

Instructions

Learn More About Fluval From Our Team of Experts

Questions & Answers

3 Customer Questions


will this work for the 2.6 gallon tank? Or the 5 gallon tank? I have both.

Answer by ChewyMar 06, 2018
The Fluval Underwater U4 Filter and Cartridges are recommended for use in 34-65 Gallon tanks.

Will this work for Fluval canister filters 307 or 305?

Answer by ChewyAug 13, 2021
This filter cartridge is specifically designed for use in the Fluval Underwater Filter for Aquariums, Size U4.

What are the filter's dimentions?

Answer by ChewyMay 31, 2021
These filters measure approximately 6.7 x 2.8 x 1.8 inches.
4.3
Rated 4.3 out of 5 stars
29 Ratings

12 Customer Reviews



Rated 1 out of 5 stars
By James on Aug 11, 2025

Disappointed and busted

47 lb bag of food on top of fragile items and box was broken and tapped. Cherry was always good. This order I lost 75.00 of items. Even the food bag was broken

47 lb bag of food on top of fragile items and box was broken and tapped. Cherry was always good. This order I lost 75.00 of items. Even the food bag was broken and spilling out


Rated 5 out of 5 stars
By Deborah on Aug 18, 2025

Just what I needed

Needed this for my turtle tank. They are hard to find sometimes but found them here and the price was okay.

Needed this for my turtle tank. They are hard to find sometimes but found them here and the price was okay.


Rated 5 out of 5 stars
By Rah on Jun 20, 2025

Turtle Tank

Perfect for the Fluval U4

Perfect for the Fluval U4


Rated 5 out of 5 stars
By John on Feb 2, 2025

Price brand name

Works great in my fluval filter

Works great in my fluval filter


Rated 4 out of 5 stars
By Donald on Nov 20, 2023

unused

I haven't used it yet but really like these filters. They are easy to change

I haven't used it yet but really like these filters. They are easy to change


Rated 1 out of 5 stars
By Brett on Jul 17, 2021

Misleading

Bought this due to it recommending it as a compatible filter for rf-s top fin product and it is completely WRONG. Why are filters impossible to locate or fit in

Bought this due to it recommending it as a compatible filter for rf-s top fin product and it is completely WRONG. Why are filters impossible to locate or fit in my tank?!


Rated 5 out of 5 stars
By BFFs on Apr 22, 2019

Only the Best for the Turtles

I use fluval products for my underwater filter systems they are great!

I use fluval products for my underwater filter systems they are great!


Rated 5 out of 5 stars
By Kelli on Mar 31, 2019

They actually filter..

Massive turtle poo. Not sure what else is needed. These go with my Fluval F4 and that’s all I got to say about that..............

Massive turtle poo. Not sure what else is needed. These go with my Fluval F4 and that’s all I got to say about that..............


Rated 5 out of 5 stars
By steph on Aug 6, 2018

works great

great price for an amazing product, i use this in my res turtle tank and it keeps the water crystal clear

great price for an amazing product, i use this in my res turtle tank and it keeps the water crystal clear


Rated 1 out of 5 stars
By Lucky on Jul 22, 2018

stay away waste of money

WATER IS GREEN AFTER 4 DAYS, I changed 3/4 of water and again in four days I could barely see my fish. never had this problem before using this system. Wasted my

WATER IS GREEN AFTER 4 DAYS, I changed 3/4 of water and again in four days I could barely see my fish. never had this problem before using this system. Wasted my money and my time with this product. My service from Chewy was GREAT ,just a bad choice from Fluval!!!!