Matt, I let my siphon "hover" over the stuff on top of the sand, and gently siphon the sand in the "eating area". I tap the doo hicky on rocks and stuff to get the sand out. Some of the sand is sucked up, but my nasty water goes into my flower bed so no big deal!
I used play sand in my 200, and colored play sand in my 30 ( its blue), and gravle in my 75. Gravle definatly sucks, sand is way easier and plants and cat fish love it.