Pond carbon uses a process called chemical filtration which removes dissolved organics from your water garden. These organics can make the water yellow in color. Pond Carbon will remove colors, odors, medications and other impurities to help make your pond water clearer. It is recommended to use carbon on a intermittent basis. Pond carbon needs to be placed in a mesh bag to contain it. Once the pond carbon is in a bag, it can then be placed in an area of high water flow. Some recommended areas include: underneath a waterfall, inside a up flow waterfall filter,biofalls filter, canister filter or other types of pond filters. Each container of carbon comes with one mesh bag, a $4.95 Value Pond Carbon 5 lbs. PC5 Pond Carbon 9 lbs. PC9 ponddepot@msn.com Copyright - All World Rights Reserved Pond bacteria, Pond Kits and Pondless Waterfall kits, Filter Pads, Underwater Pond Lights. pump replacements and pond algae control. Pond Depot provides excellent technical assistance and fast shipping for all orders. The staff at Pond Depot are highly trained and experienced in installing and maintaining ponds. We will gladly answer any questions that you have. Pond Depot your online pond superstore!