Been having some issues trying to get my pool open. Had been using an old pack of test strips and realised they were very out of date resulting in I think me adding too much stabiliser to the pool, so ordered some more tests (different brand), replaced half the water and this test contains a Clorine and bromine indicator (I never tested for bromine before). I was not expecting to see any bromine indicated as I use a SWG but the test came back with both Clorine and Bromine, Bromine quite high (10-20ppm), Clorine at normal levels of about (3ppm). Is this just the tester reading chlorine as bromine or do i really have bromine levels that high? Where could the bromine have come from otherwise?