How deep is the pool at the end where the stairs will be, and what height and tread depth do you want for each stair? Are you willing to install a rail? My stairwell is only 1m20 but the stairs are quite steep, there are only three, and the bottom one is high. Pool depth is 1m60 bottom to deck. This arrangement required a rail. You have to calculate number of stairs x tread width. A lot of low stairs with deep treads are going to require more horizontal space but will be easier to use. I'd make steps higher rather than skimping on tread depth. Be sure to make a deeper tread at the top if there's an overhanging pool edge.