I put in a new sand filter about a month ago and whenever we run the filter, notice sand (looks like beach sand) and some debris on bottom of pool, particularly around the returns. The Polaris picks it up and it remains clean until the next time we run the filter and the sand returns to the bottom again.
I called out the company that installed the filter, and after poking around they swore that there is no way it can be the filter sand returning into the pool. They said "you must have a busted pipe under the concrete or something."
Hoping someone on this forum would be able to help. Just FYI here are my chemistry numbers