Sand & silver Dollars

[AquariCam]

Somebody that visits my little site is thinking of changing his substrate for sand. Apart from the implication of moving his fish and strength of filtration in the tank, will he have problems with 3 (almost) adult Silver Dollars and a sand substrate?
I personally think they will be fine, however, if I had sand in the tank that houses my 5 adults they'd have it all stacked up on one side within a day and the water would be permanently cloudy.

Thanks (as always) in advance