I've been noticing that in many of the hot tubs I regularly maintain, that for some reason, I'm not seeing Bromide being converted back to Bromine like I did in the past. In some tubs that had too much Bromine added in the past, I would see the water turn yellow when I added MPS. In most others, I would see FC show up on a test strip. Lately, I've been noticing that in many of these tubs, neither of these things are happening. When I started noticing this, I filled the floater with bromine tabs and put it back in the tubs, but now I'm noticing the tabs don't seem to be dissolving in many cases. Is it possible that there is just so much to be oxidized in these tubs that the MPS is being occupied by organics so I don't see the Bromide converting to Bromine?