Bulk Reef Supply

Color Changing CO2 Absorbent Media

Grouped product items
1.2 lbs (Single Cartridge Refill) Color Changing CO2 Absorbent Media

SKU: 211840

In stock

$4.89 $6.99

- +
7.5 lbs Bulk Color Changing CO2 Absorbent Media

SKU: 211841

In stock

$25.89 $36.99

- +

Raise your Reef Tank's pH by controlling Carbon Dioxide!

Bulk Reef Supply Color Changing CO2 Absorbent Media (Soda Lime) is the perfect solution if your aquarium has a low pH but proper alkalinity levels. It is most commonly used by connecting a carbon dioxide scrubber to your protein skimmer's air intake and can produce substantial lifts. We package the media in Mylar bags and then seal them to preserve the hydration of the media, leading to longer service life and the ability to absorb more CO2 than others on the market. We suggest purchasing single cartridge refills, but if you have higher carbon dioxide levels in your home or business the bulk packaged media is going to be more economical.

  • White to purple color change indicates depletion.
  • Minimal dust levels due to the high surface area and graded particle size.
  • Reliable control of indicator dye concentration.
  • Resistance to dry gas desiccation minimizes the risk of CO gas formation.
  • Doesn't contain potassium hydroxide.
  • Packaged in Mylar bags to preserve the hydration state.


Two Sizes Available:

  • 1.2 lbs - 1 Single Cartridge Refill (approx 800mL)
  • 7.5 lbs - 7 Single Cartridge Refills (approx 5600mL)

7.5 pound bulk media comes in a resealable mylar package


BRS Carbon Dioxide Absorption Media is made of calcium hydroxide (Ca(OH)2), water, and a small amount of sodium hydroxide (NaOH) in a precise mixture that will efficiently remove CO2 from the air in a semi-closed system. The addition of ethyl violet dye is added to the particles as a color indicator to show when the media is nearing exhaustion, making maintenance as easy as looking at the canister containing the media periodically. The irregular shaped granules add to the available surface area, allowing more air to media contact time, while the granules also fill any voids and help minimize channeling through the cartridge and may not last as long as spherical media, but is much more effective. 


Instructions for use

1) Fill your reactors refillable cartridge with BRS CO2 Absorbent Media

2) Add one teaspoon of water to the bottom of the filter canister housing (not the cartridge). Do not get the soda lime wet.

3) Connect the output of the reactor to the intake of your skimmer.

4) Keep an eye on your aquariums pH and the color of the media and replace the media after it has turned purple or the pH is starting to drop*.


*It is essential to replace the media after it has exhausted. If exhausted and left to stand CO2 absorbent media will revert back to a white color, and may appear fresh but is actually not usable anymore. BRS CO2 absorbent media cannot be regenerated and should never be re-used.


How Long Does It Last?

Since every aquarium and the environment around it is different, the amount of media used can vary greatly from one home to another. In most cases, BRS CO2 Absorbent Media will last up to two weeks per single 10" cartridge, but depending on the amount of CO2 present in the air around your tank, the lifespan of the media will vary. Keeping the carbon dioxide levels in your home lower will help increase the lifespan of the media, which can be done by opening windows and using screen doors allowing fresh air inside your home. Another great option is live plants inside the house which will help minimize CO2 levels as well. 

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Product Questions

Can this be used in an RODI system set up to decrease CO2 levels to decrease how much DI resin is being used?

Question by: Ashley Hieronimus on Jul 12, 2023, 7:47 PM
Hey there,

Thanks for the question. This would not work in that set up. This is designed to scrub the incoming air of CO2 and connected to a skimmers venturi inlet. If this media gets wet it essentially be kalkwasser and clog your RODI unit. Thanks and have a great day!
Answer by: Codey on Jul 24, 2023, 2:58 PM
Does the 7.5 lb bulk order come with 7, individually sealed, single serve cartridge refills or is the full 7.5 lbs sealed in one mylar bag?
Question by: Eli on Jan 30, 2022, 9:39 AM
It comes in one big bag.
Answer by: Matt Lucero (BRS Staff) on Feb 2, 2022, 2:44 PM
What reactor does a single use bag (the 1.2 lb) fit in? The standard size, or one of the jumbo reactors?
Question by: Corey M on Sep 14, 2020, 2:23 PM
Answer by: Matt Lucero (BRS Staff) on Nov 5, 2021, 9:00 AM
I'm using this in a TLF 150 Reactor and the instructions say to add 1 tsp of water but to not get the soda lime wet. In the past I have just skipped adding the water. What is the risk of getting the soda lime dust wet?
Question by: Jacob Ohl on Jan 19, 2020, 5:09 PM
Hey there!

The idea behind the water is to create a humid environment for the media, it works much better. However if the media gets wet it can disintegrate and not work properly and even clog.

Take care
Answer by: Thomas Billington on Jan 22, 2020, 3:32 PM