There are assorted critters that you can find in your skimmer that come from a multitude of places--some will crawl to the water supply, some can come off of pets, birds and other creatures that drink out of the pool at night, etc. You don't need to do any thing special--dump your skimmer basket, make sure your chlorine is adequate, and go swimming!
A whipworm is probably not the grossest thing you'll ever find in the skimmer throughout your years of pool ownership..........
Janet
Bookmarks