Check the listing for details. SeaGel (250 mL) - Seachem. Condition: New. Listed at 7.91 USD. SeaGel™ is a blend of MatrixCarbon™ and PhosGuard™. MatrixCarbon™ is an ultracapacity carbon for the removal of organic and color impurities. PhosGuard™ is a powerful remover of phosphate, silicate, toxic metals, and acids. Both components are bead shaped for optimum water flow characteristics and penetration. The components enhance each other and are ideal for reef and marine use. SeaGel™ may also be used in freshwater that is not phosphate buffered. Although MatrixCarbon™ has the lowest detectable leachable phosphate content of all major carbon brands tested, some phosphate is still released. Adding PhosGuard™ to the mix compensates for this. Both components are bead shaped for optimum water flow characteristics and penetration. The components enhance each other and are ideal for reef and marine use. Listing and template services provided by inkFrog