I'm trying to get some information and advice on how best to repair/resurface my pool bottom prior to installation of a new vinyl liner. The pool is 20 by 40 with 42 inch steel walls and what I'm guessing is a sand/grout mix bottom. I'm located just outside Toronto, Canada. The present bottom has many crumbling areas and wash outs and is covered with algae in a lot of places. It is quite uneven in a lot of places and the goal is to even it all out to get it level. It has been suggested I use the vermiculite pool base recipe to cover over the existing base. My question(s) is how do I go about prepping the existing base if I'm going to top coat it. How thick should I go with topcoat, should I use any sand in my mix or just Portland and vermiculite alone? Also the transitions in the deep end hopper walls are radiussed (curved) and not defined angular transitions like I've seen in videos of new installations - should they be changed? Also there is quite a bit of corrosion on the steel walls - do I just sand these down and spray on a galvanizing compound? A lot of questions - just want to be informed when I talk to my contractor or even if I want to tackle it myself.
Thanks for any help or advice!