7.5 lbs Bulk Color Changing CO2 Absorbent Media - Bulk Reef SupplyRaise 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