Check the listing for details. Seachem SeaGel Removes Phosphates, Silicates and Organic 250ml. Condition: New. Listed at 12.97 USD. SeaGel - 250 ml Ideal for use in both freshwater and saltwater aquariums, Seachem SeaGel is a proprietary 50/50 blend of Seachem MatrixCarbon and PhosGuard filter medias designed to remove phosphates, silicates, organics, metals, acids and more. MatrixCarbon is an ultracapacity carbon media that contributes to the removal of organic and color impurities in your aquarium where PhosGuard on the other hand efficiently removes harmful phosphate, silicate, toxic metals and acids. The comprehensive mixture is much more convenient than purchasing two separate media bags, and is ideal for aquariums where organic color and acid removal is necessary without the use of phosphates. The media mixture is bead shaped to help optimize the flow of water passing through and over it, allowing for more success in the aquarium. Comes in a 250 ml container.