I'm unclear about something. The HTH Spa Non-Chlorine Oxidizer Tablets that were added are potassium monopersulfate (MPS), not bromine or bromide. I don't see where any bromine has been added to this pool. Bromine is often effective at killing pink algae and especially so in this situation since the CYA is so high that chlorine is simply not going to do the job (unless there is significant water dilution first to lower the CYA level). So adding some sodium bromide to the pool will, when activated by chlorine, produce bromine to kill the pink algae.