I quit using bromine a long time ago, but I still had a bunch of frog mineral cartridges. I decided to keep them for winter use. Anyways, I use dichlor and since our tub doesn't get much use, I only filter two - one hour cycles per day. Whith dichlor only, the tub will go cloudy in about five or six days. Whith the mineral cartridge installed, I just went 14 days without evn opening the lid and the water stayed crystal clear. I added a small dose of dichlor and checked 24 hours later, still a residual. Bottom line, the minerals are a great standby if you don't use the tub much and don't like bromine.
Steve