If they installed the pavers correctly and cleaned up after themselves there shouldn't be loose sand to blow into the pool. If they left too much sand behind use a broom and light pressure from a water hose to clear the excess sand away from the pool. Turn your pump off overnight and let all the sand in the pool settle to the floor and slowly vacuum the sand out with a manual vacuum. The key is to work slowly and not disturb the sand on the pool floor too much. It may take a few days to get all the sand out.
Now if it looks like you are getting increasing amounts of sand collecting on the pool floor it may not be sand but algae you are seeing. A way to check is to collect some of the debris from the pool and place it on a white sheet of paper. If the sand puffs away when you try to collect it then it may be algae. Algae will puff away in a fine cloud. Sand should feel gritty and algae will feel papery or slimy. Algae will leave a greenish smear on white paper and look powdery when dry.