I made a silly mistake of not reading the instructions and added 5 Kg of a product called Refresh which is borate. What a did not realise was this product increased PH. After 2 hours checked pool and had white blochy stains where I had pured this stuff. I tried brushing which did nothing. I checked PH and it was 8.4 so I immediately poured .5 kg of acid and after about 20 minutes I noticed some of stains had lifted a bit and PH had dropped to about 8.2. I dropped another .5 kg and waited for another half hour brushed a bit more and noticed they were slowly disappearing. After 2 hours and more acid being injected by auto unit PH had dropped to about 8.0 and stains were virtually all gone. Eventaully got PH back to 7.5 and with continuous brushing they have all gone.
Was this calicum building over the powder I dropped in pool and consequenetly trapping it creating the white stains.