I have an existing 18X40 pool and I’m fixing to replace the liner. The original builder only put one skimmer and 1 return. The pool does not have a main drain. I never thought the pool has enough circulation because the pool always built up fine debris in uneven spots on the pool bottom(both shallow and deep end). Would I get more benefit from adding a main drain or 2 more returns? The returns are much easier to add and that’s what I’m currently planning. Thanks for your advice! Ryan
I would recommend adding two more returns. They will give you more movement throughout the pool. You could always use an automatic vacuum and that would become a moving main drain.