Someone please correct me if I am wrong....I think the formula is:
(tank L* tank W)*Depth (sand desired)*0.057=lbs of sand needed
I might have that wrong......I apologize if I do.....MCF
The formula I use is length x width x desired depth of sand bed x .0579 = lbs of sand needed(all measurements are in inches)
You don't actually need to use all LS either...I'd suggest 20% of the total be live...the rest can be dry sand(I prefer a combination of Caribsea sea flor grade and oolitic sands)....good luck establishing your DSB.