There is no reason to stick the vac into the sand like you have to with gravel. You merely skim the top to pick up the poop or any uneaten food. After you are done with that then you want to stir up the sand slightly once in a while to allow any bacteria pockets to be taken care of. PFS will allow you to skim the top though without picking up any sane really. You might get a tiny bit but nothing you will notice.
I use a small strainer in the sink whole that catches the sand and it catches the sand regardless of how hard I try not to vacuum it up. The tricky part with sand is when you have hard to reach places or under decorations. You have to tilt a certain way and can't help but suck up the sand. Even if you hold it above, you still have to get low enough to suck it up and you still suck up sand. I think it may also depend on the power of the faucet, I can't hold it farther than an inch or two off the surface, anything more it won't suck it up. Sand can be a real PITA for vacuuming. I have a pleco that craps everywhere, end up having to move decorations every time just to get to it.
