Last year In 2017 we have pool refurbed and painted plaster with Tahoe blue. I researched thoroughly before using my floatron and was assured it would not affect color. Over the past year the Pool lighten to pale blue grey. I brush often and cHeck water levels weekly. Guy at local pool company said it was floatron. Can you explain if this is normal? Company who did refurbed left town and one of their contractors said we needed to pay to have it acid washed to bring back color. Again, is this to be expected because I feel like they are praying on the consumer.