I have a hot tub that uses the Spa Frog system. It has a mineral cartridge and a chlorine/bromine cartridge. The mineral cartridge releases silver chloride that works in conjunction with the chlorine/bromine cartridge. It helps reduce the amount of chlorine/bromine needed to sanitize the water. The silver chloride is apparently kept around the 200ppb level. Is there some way to test whether the mineral cartridge is working or not either directly or indirectly? Would silver chloride affect the ORP?