I am in the process of building a DYI vinyl liner pool. We just filled it up with city water from our house taps about 3 weeks ago. The water looked great until we had a hard rain about a week ago and now the water is quite cloudy. Attached are a few pics. I shocked the pool and ran the filter continuously for the first 3 days and ran my robot vacuum a few times but nothing so far has made much of a difference. I think the rain was so hard it was splashing muddy water into the pool and the particulate is so fine the sand filter may not be catching it. The pool guy at Leslie's tested my water today and told me to add 2 1/2 lbs of dry acid and sold me some Alum to put in after. Said it would make the particulate heavy and sink to the bottom where I could vacuum it out to waste.
I know very little about pool chemistry. I've just order one of the test kits recommended in pool school and am reading and trying to take in all the information available on your very informative site. Any advice would be greatly appreciated.