Ended up going to a different lfs
much more helpful, they actually have seachem products. The place I was going to before didn't even have a display tank :|, this one had 2 marine displays, africans, a giant gourami, sea urchins god knows what else.
Walked out with some seachem stability and a 10kg bag of crushed coral. They showed me the sump they use for all there african tanks, the bio material was just large crushed coral so i'm filling my canister with that. He tested the pH and was 8.4 with one of those digital tester things.