I just bought a house that came with a 20 x 40 rectangular in-ground pool. I have done some fair amount of research on Google and Youtube on how to maintain and own a pool. I'm thrilled a site like this exists which will be so helpful for me to be successful pool owner. The previous owners of the house have not opened the pool in 6 years! They were quite elderly and didn't use it anymore. They did winterize it each year but the pool is as black as black can be with dirt and debris, even the shallow 3ft end its hard to make out the bottom in a full sun. I have pros coming this year to drain it, acid wash it and refill it. See you on the threads!