Well Long story in short, we are moving into my In-laws former house, watched this beautiful 45,000 gallon oblong ish concrete/plaster pool get worse and worse over the years and now its my dont want to call it problem as we are very very happy to have it but needless to say when I just asked him when he closed the pool this year what did he use to blow the lines out (this is central indiana and we are below freezing well below freezing alot) he said he never has in almost twenty years..... He did drain the filter and pump thank the lucky stars. Every year the pool starts out black/green and maybe by the end of the summer he had it so you could tolerate it. Though last year he had it so out of whack getting water in your eyes was about like getting C.S. gassed.... I am/was a stone mason so ill be building a Beautiful outdoor grill this summer too. Anywho enough with the rambling, as I am a disabled stay at home dad so youll probably see me around here quite a bit.