I have a 24 x 16 above ground doughboy pool, and ive left it open all winter here in the dallas,tx area. Ive noticed a month ago what I thought was sand to poss be mustard algea, I performed the yellow out last week, and shocked every 12 hours until instructions were completed. I brushed everyday, I also had all equipment in the pool to sanitize as well. It really seemed to work great, for I had a lot of white clouds on bottom of the pool, which after treatment, I vac'd all of it out to waste..I could tell it was still working days later, for you could see little white clouds still killing the potential algea,but now its back to that brown / yellow look. It seems to come back in the same spots. Its not bad, but still irritating. My pool is vinyl, so I dont want to shock too much, and weaken vinyl...Do I need to perform the yellow out again? calling for rain next two days, so wait? My readings from last night are below:
ph=7.5
cl=10
alk=90
cya=50
ph=7.5
cl=10
alk=90
cya=50