My new pool was plastered last Thursday, June 28 and filled by Sat, June 30 with city water. The free Chlorine Level is within range according to test strips but the PH is still a couple of shades high. From Wed to Thurs, about four dime sized rust colored stains developed in an isolated area of the pool. They are in the mid point, on the floor, right at the edge. I skimmed the night before and removed as much debris as possible and I've been brushing at least 3 times a day. I haven't used any type of vacum cleaning device under advice of the service department. I've flushed the DE filter twice so far.
Is there anything/what can be done about these stains this early or must the plaster cure longer?