This listing is for high quality granulated activated carbon， for use in both freshwater and marine aquariums， along with ponds. Quantity for sale in this listing: 500gCarbon will remove any toxins from your water， and will give the water a final ??polish?��， leaving your water crystal clear!Why waste your money buying pelleted activated carbon?Traditional pelleted activated carbon has a very low surface area. The even shape means that only the outside surface of the carbon is exposed to your water， so the middle area never actually does any filtering.The more surface area which is exposed， the more carbon you actually get for your money! This is why we supply granulated activated carbon， which has a huge surface area compared to traditional pelleted carbon， saving you money!This carbon comes supplied in a large grip seal bag， so you can remove the amount you need， and then seal and store the rest.FREE MEDIA BAG ALSO INCLUDED! We are now including two free small media bag， ideal for most aquarium filters. The media bags are of size 14.5cm x 11cm.