Katadyn Filter Can Bulk Activated Carbon Be Used In Water Filters?

Can bulk activated carbon be used in water filters? - katadyn filter

I have a water filter Katadyn Combi. Sachet Filling carbon since they are expensive. There are many places to buy coal blocks are relatively cheap. Physically, it is a trivial task to buy in bulk and use in the filter, but I wonder suited me about the quality of coal, as is, and how carbon filter or something else I have to consider when buying in large quantities carbon.