If you want regular "tan" sand get pool filter sand (it's really cheap at $4-7/50lbs, depending on where you buy it - Lowe's carries it, Leslie's pool supply has one that's more white), and it's 100% silica... play sand can have other stuff in it like crushed limestone that isn't exactly a good thing to put in your tank... some people have used play sand without issue, but others have had problems, and unfortunately you never know what your play sand will actually contain before you buy it.
I've used caribsea sands and the moonlight (white) is the finest and hardest to work with IMO.. you move anything in the tank and it goes everywhere. The tahitian moon is fine, but not quite as fine as the moonlight, and it doesn't blow all over the place as badly. They also have some really nice looking coarser sands... petsmart/petco don't carry them in store but my LFS does and I almost used one of them in my 55, but I ended up doing eco-complete capped with tahitian moon... it looks really good, the background in that tank is black too, so the plants and driftwood really pop, but I have no fish in there yet... I plan to have a small army of dwarf corys and an assortment of community fish.
Also, if you attach some toothpicks to the end of a gravel vac with some rubber bands, you can stir up the debris on top of the sand without sucking in too much sand.. I've pretty much accepted that I'll be sucking out a small amount of sand over time... if any of my tanks start to look like it needs more, I'll just add more.
Last edited by sarahspins; 10-01-2012 at 05:38 PM.