Fluval U3 Poly/Clearmax Filter Cartridge, 2 count

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Keep your Fluval U3 Underwater Filter working effectively and help to control green water and algae growth with Fluval U3 Poly/Clearmax Filter Cartridge. Fish waste, uneaten food and other organic matter can build up in your aquarium water, causing algae growth and increased phosphate, nitrite and nitrate levels. Raise these levels too much, and they can be harmful to fish. This filter cartridge helps to absorb and trap these pollutants, protecting your aquarium and those who call it home. Designed for the Fluval U3 Underwater Filter, Fluval U3 Poly/Clearmax Filter Cartridge supports crystal clear water, helps to control odor and works to reduce overall aquarium maintenance.

Key Benefits
  • Helps control green water and unsightly algae growth for a clear, beautiful tank.
  • Chemical filter media helps to absorb and trap phosphate, nitrite and nitrate.
  • Encourages crystal clear water, helps to reduce odors and encourages the ideal conditions for fish and plants.
  • Helps to reduce overall aquarium maintenance, so you can enjoy your tank more and worry about it less.
  • Convenient two-pack gives you one cartridge for now, and one for later.

HAZARDS TO HUMANS: Always disconnect appliances in the aquarium from the electrical supply before placing hands in the water, before putting on or taking off parts, and whenever the filter equipment is being installed, maintained or handled. Following a routine maintenance schedule will result in a healthier aquarium and extend the life of the filter. Fluval filters have been designed to facilitate these tasks as they can be done within a matter of minutes. For best results, please follow our maintenance schedule recommendations.

Compatible with this Fluval Underwater Filter.

See all items by Fluval

  • Item Number
  • Aquarium Type
    Freshwater, Saltwater
  • Fish Type
    Tropical Freshwater, Marine Fish
  • Material
  • Replace Alternate Foam Pads every 3 - 6 months.

  • Do not replace all Filtration Cartridges at the same time. Alternate Filter Cartridge changes so that some older cartridges remain in use. This ensures the re-seeding of beneficial bacteria, so that colonies discarded with older cartridges will be replaced by vigorous new ones. To enhance bacterial action, pour a dose of biological aquarium supplement onto your Filter Cartridges each time you change the media.

  • Unplug the power cord.

  • Open the filter cover (to make the operation easier and in case the filter is positioned under an aquarium frame, tilt the filter forward until it stops but make sure there is enough electrical cord to allow the filter to pull forward).

  • Slide the Foam Cartridge Frames out of the filter body. Keeping them vertical to avoid releasing the debris collected inside the debris receptacle. Place them in an empty bucket.

  • Remove the poly/carbon cartridge from the cartridge frame.

  • Remove the foam. Rinse the debris receptacle and the foam pads using water taken from the aquarium or replace one of the foams following the recommended replacement schedule. Do not use tap water as this will kill the beneficial bacteria in your foam. Note: Never use soap or detergents as these products could be harmful to the inhabitants of your aquarium.

  • Replace the foam pad. Make sure the foam is positioned behind the tabs on the sides of the frame.

  • With the carbon side facing out, re-insert the poly/carbon cartridge by inserting the lower end of the cartridge into the lower end of the cartridge frame then snapping the top side of the cartridge under the two tabs on the top side of the frame. Do not press too hard, as the cartridge must sit on the top of the tabs on the sides of the frame. Hint: For best results, replace 1 poly/carbon cartridge every 2 weeks.

  • Slide the BioMAX cartridge out and place it in the sink or bucket.

  • Pull open the tab on the side of the cartridge, opening the cover. Rinse the BioMAX with aquarium water, never tap water, or replace half the quantity every 5-6 months. Never replace all the BioMAX nodes at one time, as valuable colonies of beneficial bacteria would be lost.

  • After rinsing, put the BioMAX back in the cartridge and close the cover. For best results, completely fill the cartridge.

  • Re-insert the Foam Cartridge Frames into the filter with the poly/carbon pad facing inwards. Re-insert the BIOMAX cartridge into the filter making sure to properly align the hole at the bottom of the cartridge directly on the top of the impeller opening. Close the filter cover and if required, snap the filter body back into position on the filter bracket.

Rating: 4.7 of 5 stars 4 Reviews 4 Reviews 4.8 out of 5 Stars

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Rating: 4.7 of 5 stars 4.8 / 5

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4 Reviews

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  • 5 out of 5 stars

    this product was great

    By turtle on Sep 3, 2020

    Turtles produce a lot of waste and the filter and the cartridges are great my water has never been clearer

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  • 5 out of 5 stars

    Fluval Filter U3

    By Rita on Mar 23, 2018

    This is the best easy to use quiet filter I love it

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  • 5 out of 5 stars

    Fluval u3 filter.

    By Sergio on Dec 22, 2017

    It's exactly what I needed. This filter is made very good. The part plastic makes it easy to install.

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  • 4 out of 5 stars

    Different from original filter

    By Larvae on Dec 20, 2017

    Not like the filter that came with the system...but so far doing a decent job.

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