We have a bromine spa and have been using a floater with bromine tabs but it seems like it does no good. Should we still expect to add a little dichlor or MPS to bring the bromine reading to normal sanitizing levels (3-5 ppm) after each use, even with a floater? I guess I expected that was the purpose of the floater-to have the bromine levels bounce back, so you don't have to add a shock each time. TIA!