SpaFrog mineral cartridge

[D.P. Roberts]

I'm thinking of switching to the SpaFrog system from dichlor - we just don't use the tub very often, and I like the idea of it being "ready to use" with the floating system. I know that bromine is an effective sanitizer; the cartridges are kind of expensive, I understand I'm paying for the convenience of easy bromine dispensing. However, I'm wondering about that "mineral" system. It's great if it actually reduces the amount of bromine I'd use, but what exactly are the "minerals", and why would I want to pay $30 per cartridge for them?

[soak-king]

I believe the mineral cartridge holds silver (similar to the Silver Ion cartridge) and Calcium Carbonate. The floating frog system is pretty neat because the empty side will be rise above the waterline when empty so you know when to refill.