Last year had two small rips in vinyl liner....shocked for two weeks water still cloudy ,,,luckily saw and rapaired it with repair kit,,,,this year with heavy leaves and dirt and a frog ,,,water as black as the night sky,,,,again daily cleaning and shocking for three weeks ,,,water got clear enough to see 2 more small holes in liner....so that is my tip of the day,,,,really inspect liner if you keep chlorine levels up and sill cloudy....I should have known something wasn't right ,,,when we vacuumed out weeks ago lots of sand so I discharged right to waste by-passing filter...I found it last night so I put my pool brush on the end of my extendable pole over the hole and wow what a clearer pool this morning ....couple ???? What is the life expectancy of a vinyl liner and if I replace liner next year with a fancy rock design would these small holes be harder to see ??? Thanks