We have a "y" connector to the external water bib at the back of house. I I can turn off the water flow to each side of the "y" connector. One side of the "y" is connected to my garden hose. The other side is connected to a valve and pipe that goes underground to the other side of the pool, and comes out of a small wall about a 18" above the water level, and is what is used to top of the water level. When I turn the water on at the bib, to top of the pool, and open up the valve, the water starts pulsing and knocking about 2-3 times per second. You can hear it inside the house also. It will go away if I close the valve about half way. If I just fill the pool with the garden hose, there is no problem. Any thoughts on what might be causing this?
Thanks.
Thanks.