In advance, thank you for all the helpful responses I know I will receive.
The back story....my pool had some trouble with metal staining (due to high chlorine and high Ph (?)) after I shocked at the end of last season due to some algae (got rid of algae beautifully). Then I performed the ascorbic acid treatment to remove the metal stains and it worked beautifully. I brought Chl back up slowly and pool looked crystal clear and lovely all winter long. Now that spring has sprung here in Florida, I have turned on the passive solar and pool is warming up nicely. There are a few spots (very few) of green algae. Vivid green. Easily brushed off. Due to pool warming up? Also, AND OF MOST CONCERN is some of the metal staining has started to reappear. To avoid the metal stains reappearing I have kept pH low and added sequestrant (Purple Stuff) weekly. Why are they reappearing? Not really bad yet but AGH! After the pool had been so beautifully white and stain free.
My confusion......my levels all seem about right....I know CYA and FC are low but I have done that to keep algae at bay -- they are still within advisable levels.....and shouldn't I be keeping them on the low end to avoid the metals restaining pool? What am I doing wrong? What should I shoot for chemically to keep algae from forming and keep the metals from restaining pool? THANK YOU. THANK YOU.