Only the inside hole has to be plugged. Just so long as the water needs to come over the top and through the surface skimmer teeth, you will be fine.There are two layers of plastic with a air space in between. The hole was cut through both layers of plastic. Suppose each hole needs sealed up individually or don't worry about that?
Only the inside hole has to be plugged. Just so long as the water needs to come over the top and through the surface skimmer teeth, you will be fine.
Air gap?