I have 5 years old BR fiberglass pool in Reading, Pa and whitening/bleaching/discoloration is happening at alarming rate now. Contacted BR and they replied. They call it hybrid scale which is similar to calcium scale but doesn’t react to any chemical removal. They sent me Pool Tiger device to put on filtration line and see progress over the next few month. I just did. I feel we should go to litigation and get them to redo gelcoat on all our pools.