Since I put a regular floater in, my bromine levels have been more consistent. I'm not sure if there's something about the spafrog granules or the dispenser itself, but even with it wide open, I was having trouble keeping bromine levels up. We tried it because the dealer gave it to us on delivery, with our old tub, we had always used bromine tabs with good luck. I chased bromine levels for a month, then got a floater and I'll probably just toss it when the mineral cartridge is used up.