Next weekend I will install a Pentair Tagelus TA 100D sand filter. It requires 600 pounds of media. I plan to use a pea gravel base of 150 pounds and top that with 450 pounds of silica. Pool stores (Leslies and mom/pops) around town want $10-$12 for a 50 pound bag. Lowes charges $9 for a 100 pound bags if silica 20; they stock it in the masonry aisle. The bag mentioned a several uses for silica sand but did not list swimming pool filters.
Q1: are all silica 20s the same?
Q2: what is the best way to extract sand from the old filter? I'm thinking of a coffee can attached to a pole and scoop it out slowly.