Well..............the project has begun. I am 1 week into my 21X43 AGP with hopper liner. I just poured the concrete footers yesterday for the deep end side uprights. So here is my question for planning ahead. I have a dig sheet for the beaded hopper liner, but am wondering if this is the dimension before or after my base material? This is a hopper liner and not an expandable liner. I'm thinking this needs to be right or the hopper won't fit and i will have wrinkles. So should I just dig according to my dig sheet and then put in my base material? If so how think do you guys make your base, 1-2 inches? My plan for my base material is what they call around here is pond silt. It looks like pool sand mixed with a fine clay. it holds together and packs nicely but is finner than sugar.