A standard carbon block works well to remove chlorine, however, more and more municipalities are adding ammonia to the water treatment processes to stabalize the chlorine from releasing harmful by-products into the water. As you may know, ammonia is toxic to marine organisms and this filter is the only pre-filter to effectivly remove this harmfull chemical. The NH2CL (Chloramine) Blaster upgrade kit, will remove the chlorine + ammonia also known as chloramines before passing through the reverse osmosis membrane, therefore extending the life of your membranes and deionization (DI) filters. Our NH2CL Blaster filters also have a longer life span then the standard carbon block. The NH2CL (Chloramine) blaster works effectively only when run in series to allow enough contact time with the water, that is why an extra canister is provided. To install this upgrade: * You transfer your first sediment filter into the single canister provided * Discard your current carbon block, and place the 2 NH2CL Filters in the 2 empty canisters on your system. * Use the provided tube to connect the single canister with sediment filter to the beggining of your system, and * Connect the feed line to the sediment filter.