I have a 22’ x 52” Intex Ultra Frame pool I plan on putting up tomorrow. After getting it set up and start filling with water i plan to get in the pool and work the wrinkles out. I have a salt water system to hook up, is it better to put a little salt in at a time as the pool fills or to wait until it is full and add it all at once? Is there any other chemicals I should add on start up? Also, are there’s any chemicals that ever need added after a rain or anything, or should the salt water system take care of everything?