Spotted sand in my pool

I have been spotting what appears to be white sand in my pool. It is as dense as sand. This is the first time that i'm spotting this in my pool and hoped it would be from any nearby construction sites presence. But later on,m After a detailed check, I came to know that there wasn't any construction taking place nearby. DH had called upon for swim spa installation services of Ferrari Pools in Boston ( http://www.ferraripools.com/pool-service-maintenance/ ). Are there any DIY ideas ?