I opened the pool this year with no issues. Went to the pool store on Memorial Day and my phosphate reading was 1100. I accidentally put too much phosphate remover in the pool. This morning I opened my filter and found what looks like white mold that has grown on the filter I found it on the skimmer basket as well. Went to the pool store and they told me it was a byproduct of the phosphate remover that I put in. My phosphate went from 1100 to 550. Wanted to know your opinion on what this is.