Last year I posted an idea that I never tried. It was to use pool water rich in CYA (mine was 120) to feed my lawn sprinkler system. Then top up the pool with city water. Over the course of the summer the CYA should steadily drop as the pool is diluted so long as no more CYA is added.

Doing this job in theory will work. In practice this inter-connects two systems in a way that could get complicated, and no pool or sprinkler company would work on it if there ever was a problem.

Doing this manually on a dry summer day is an alternative where your lawn will love that pool water, and you can keep topping up the pool with a hose. You will need a draining pump for the pool, or use the backflush line on your filter.

Jim