A wading pool for a KIB moat will sometimes have a slow air leak from the valve. This step-by-step procedure will solve that problem.
Your repair involves only the male part of the valve...
Scrub the entire outside of the male part of the valve with very course sandpaper
Using a very small straw, cut a shor piece as shown
Slice your straw piece once as shown
Overlap to make a snug fit inside the male part of the valve
Your new valve