My wife and I bought a 10 year old house in CA. The pool is only 6 years old, but there are small circles of cracked plaster throughout the pool. I can only assume this is due to a severe lack of maintenance, as the house was a foreclosure. There has been an ongoing issue with algae, which I have got under control, however I fear the plaster needs to be redone, due to the spots where algae ate the plaster. The areas of missing plaster are making a beautiful new pool appear worn and aged! Do we need a contractor to come out and replaster the pool, or is this possibly a diy project for the winter? If this is a diy project, how long can the pool remain empty prior to damage occuring? This is a very large approx. 40,000 gallon pool, so if we were to go at it ourselves the project would take several months to complete. If replastering by a pro is needed, I would like to add the crystal blue quarts finish and possible remove the automatic pop up jet cleaning system, as it doesnt work nearly well as advertised, unless there are issues with the cleaning jets as well. Any help would be appreciated, as we are new to pool ownership!