Go on the MD website.. under "education" sand calculator using "med sand ratio" Don't judge by petsmart ad.. their heads are up their arses! said for 4 in bed in a 48 x 18 I something like 480 lbs! .. one lb per gallon /per inch! lmao!..
I took advantage of this as well. I almost feel sorry for MD because I'm sure they get screwed in shipping costs. I actually tried to order from PetSmart because I'd rather screw them over than MD but PetSmart said they couldn't deliver the product to my address.