I'm looking to build a below ground swimming pool using rebar and hollow blocks.

I would like to do the pool over 2 levels with around a steep slope in the middle to transition to the deep end but I'm not sure how i would lay the blocks to retain the structural integrity. The deep end will be 2m and shallow 1m.

I had in my head that i would wet lay the formation and set the first course of blocks and rebar into it but online there is contradicting advice.

Would love to hear some opinions

Thanks in advance.