3 year old Inground pool with vinyl liner has developed stains. What is it and is it safe to swim in?

Question

Pool company claims it is common in lagoon front homes but other neighbors are not having problems. When high levels of chlorine is added it seems to fad s but returns in one or two days. HELP!

Answer 1

scrub it and then fill it if not call a pool expert or where you got it and complain

Answer 2

drain your pool to below the stain and scrub it with bleach