Well Eric I really like the sand that Jeff Senske was using in on his award winning discus tank setup, but it doesn't have to be that pure white. I went to 2 pool supply stores- one in San Mateo and another one in San Carlos and asked for pool filter sand and they didn't know what I was talking about. I also went to landscaping supply place in South San Francisco. They had some very nice petrified wood and rocks BTW, but they only had very fine "beach sand" although they call it white silica sand it was far from it IMO. I finally broke down and picked up some 150 lbs play sand (it was cheap) at the Home Depot, but it's not really what I'm was after color-wise. More light brown than white and if I do use it, I'll have to screen it to only get the more coarse stuff.
I've purchased the sand that Ocean sells it's finer than playsand. It is completely inert, but is too fine of a grain IMO. It tends to compact (and go anaerobic??)unless you stir it up often or use trumpet snails to do that for you. If you want the sand he sells for a good price go to Broadmore landscape supply in south city. They sell a 100lbs bag of 30# or 50# grain for under $10- can't beat that.