0.5kg coral sand very coarse colonization of nitrifying bacteria

Coarse coral sand is well suited as a hardness-buffering filter medium and is used as filling material both in pond and aquarium filters as well as in calcium reactors.The large internal surface with capillary action in coral sand makes that this filter medium is considered one of the best and most efficient biofilter materials for medium-sized and large pond filter systems. The growing buffer effect provides additionally the stability of the water equivalent.Coral sand consists of pure calcium carbonate with all natural trace elements