Quote Originally Posted by Spensar View Post
"21k gallon A/G vinyl"

From reading other threads, I was under the impression that low PH will degrade the vinyl and result in a shorter lifespan of a vinyl pool liner. If so, 4.5 is not good news.
You are correct. Low pH will shorten the life of a Vinyl Liner. I told my buddy that what ever life he would have had left in his 7 year old liner, it has been significantly shortened. BTW, low pH is also bad for the pump motor, variflow valve, sides of the AG pool due to splash out, and pretty much anything else.
Amazing thing is that he has been "running" the pool this way for 7 years and has not had any problems, YET

Dave