i got enough for you. Will trade you live sand for a trade with dead sand (to replace it) or cost equivalent
In other words, if you were going to buy 20 lbs of dead sand, you can give me the dead sand, and i will give you the 20 lbs in live sand. this way you come out with live sand for the cost of dead sand, and i dont lose because my live sand will be replaced with dead sand that can quickly come to life once mixed in with the rest of my sand. You gain and I dont lose = that works.
p.s. i have a superfine sand (refugium grade) which can allow for denitrification at a shallower depth than more coarse sand and is great for sand bed fauna. but you have to fine tune your flow well not to blow it around.
i'm sure there is some sort of calculator out there somewhere.
what is the length and width of your tank.
30lbs would probably give you around an inch worth. This is the sand I have - it is $40 for 30lbs ($1.30/lb).