i have been going through this also. What you want is southdown/oldcastle sand from Home Depot, it is seasonal and some say has been discontinued. These sands are tropical sands and do not contain silica. However, i have decided to go with the caribsea sand for now since i cant wait, i will only buy two bags (30lb each) and hopefully in the near future Home Depot will get their shippment in. Below is a link to an interesting article on silica sand (some say it is safe but less beneficial). I would probably not use the tube sand, if i were to go with a silica sand i would go with white play sand, found at some home depots, i beleive it is made by a company in Vermont. I would say for you ajg1460, to check all of the Home Depots in your area, and talk to the Garden Dept., to the guy that actually orders the sand and ask him when the Oldcastle, southdown, or yardright tropical sand might come in. Also check the sticky thread in saltwater and reef general discussion, their is a thread called "its playsand season......" its like the third or fourth thread down, people list here when they find some. Good Luck!
50 Gallon Oceanic: 2 maxijet 1200's, 2 150 watt visitherm heaters, BakPak II Skimmer with PS & BT, Coralife Lunar 2X65 watt Power Compacts
Filtration: 50lbs LR
.com, 60lbs sand
Swimmers: 2 O. Clowns, Yellow Watchman, Firefish, Yellow Tang, Dottyback.
Clean-Up: Several snail & hermits, Skunk Cleaner, 2 Peps.
Corals: 2 zoo colonies, yellow polyps, star polyps