the mineral pack contains silver, zinc, and limestone. According to the mfr

"The silver controls bacteria, the silver and zinc working together help prevent algae, and the limestone absorbs acids from chlorine and shocks helping to maintain a neutral pH."

The claim is you can use less chlorine because of the use of the minerals. The erosion feeder has a dial on it to meter how much water goes through the feeder and therefore how much chlorine is put into the pool.

It is somewhat convenient to use the chlorine packs and once you have it dialed in it's easy to maintain. However the chlorine packs are expensive, so just purchasing tablets seems to work as well for me until I get my SWG system installed.