I have the pentair Dynamo 2 speed pump (3/4 HP). I run it in low speed 99% of the time, but on certain occasions I need to put it in high speed to circulate quicker. Every time I do this, I get a bunch of sand, from my sand filter, on the pool bottom. Is this a mismatch in filter to pump or what else should I be looking for? My pool is a 24' AG 54" high pool.

By the way...I never get any sand in low speed.

Thanks