Sorry for double posting, but I'm really concerned with this issue and I don't now who else to turn to.
I've purchased the house this year. The pool is about 5yr old.
I didn't have any of these dots when I opened the pool, had about a dozen a couple of weeks ago but now I have a lot more of these. I don't know what can be causing this. I've been shocking weekly with calcium based shock up until beginning of July (not because my FC was low, but because I was advised to do so as a good practice) and now my CH is about 600. The rest of the parameters look good. MY FC loss is about 1PPM overnight.
Could high CH be causing this? I also added PhosFree, Instant Conditioner about 1-2 months ago still use Leslies tablets ( because I want to get rid of some while my CYA is 30-35, PH 7.6, TA 130). Can any of these chemicals be responsible for this?
I tried rubbing them with chlorine tab, tried Vitamin C tablet - neither works on brown\green ones. I managed to get rid of some black ones with chlorine tab though. Some of these feel like bumps, (like they have heads), others are flat. Maybe the brown ones are flat, not sure
Please advise. Thanks