You are looking at a 1 pound bag of activated carbon. This is the larger rod shape not the crushed powder. What Activated Carbon Does; Activated carbon adsorbs a number of dissolved contaminants such as; chloramines and ??chlorine, tannins (which color the water) and phenols (which cause odors) Changing Activated Carbon; Because activated carbon binds with the compounds it removes, it eventually becomes ??full?? and can no longer remove any other contaminants. Therefore, it must be regularly replaced. Generally replacing it once per month is sufficient. Going for an extended period of time without replacing the carbon will not harm the tank. However, it will eventually lose its ability to remove toxins from the water. Thanks for viewing our listings. Please click "Ask A Question", or call us if you have a parts need that you do not see listed here. We will do our best to locate the parts you need, and make every effort to save you money. For parts information in English please call Chris at (813)365-0042. Gracias por ver nuestros anuncios. Por favor, envia un mensaje, o simplemente llamenos si necesita algunas pieza que no ves listado. Mencionado Haremos nuestro mejor esfuerzo para localizar las piezas que necesita, y hacer todo lo posible para ahorrar dinero. Para español llame a Darcy a el (813) 365-0042. 16B3A
