purple stain ?

[sayemthree]

inside my prefilter container (right before the pump) it is all purple . I now got some purple stain on the side of the pool and on some of the grout. it seems to be a residue - I dont think its algea. someone told me it could be from low Ph. the Ph was a little low, and I have now raied it. anyone heard of this?

[kamkuda]

It is not from a low pH. Manganese (a metal) causes purple stains, Find a sotre that can test for Manganese and remove the metals from the water.