Aitken

Hi, I have recently replaced my pool vinyl liner, my pool is rectangle shape like this one: https://www.lathampool.com/products/rectangle/. I recently discovered on the shallow flat side of the pool (3 ft underwater ) there is a piece of debri under the liner, it might be a rock, twig, or a piece of metal (may be a screw or something lying flat). Whatever is under the liner, is large enough to cause a ridge on the liner surface which is 1-2 inch long and 0.2 to 0.4 inch high. I am concerned if that is problematic, what problems it can cause, can it damage the liner or reduce the life of liner? Any suggestions on how to take that piece of debris out would be highly appreciated? Thank you in advance for any guidance and help.