Who invent swimming?
There is no specific "inventor" of swimming, as it's a natural human ability that has been practiced for thousands of years. Early historical records and cave paintings suggest that people have been swimming as far back as the Paleolithic era. People likely developed swimming skills through observation of animals, necessity, and imitation, passing down these skills through generations.
What is the hydro hook for?
How much sand do you put into a 19-inch pool filter?