Re: Safe pH levels for vinyl pools
Quote:
Originally Posted by
DurhamHouses
The joint study investigated the effect on vinyl of water pH between 2.0 and 10.0.
To make claims like this, Durham, you'll need to provide a link to the study you're citing.
Re: Safe pH levels for vinyl pools
Probably "Chemicals and Vinyl" by Don Ridpath, Pool & Spa marketing, 1998.
But this thread is all chopped up - where's the beginning?
Re: Safe pH levels for vinyl pools
It began where it shouldn't have, in the middle of a poster's questions about how to get his pool ready for vacation.
Is that article available online? If not, do you have a copy you can email me (poolforum AT gmail DOT com)? Who is Don Redpath?
Ben
Re: Safe pH levels for vinyl pools
http://piscines-apollo.com/docs/chemicals_and_vinyl.pdf
Basically if the liner is discolored it means too much chlorine, if it's wrinkled it means pH too low. pH is what kills liners. The calcium content is dissolved and the liner swells up and wrinkles. Water with high chlorine concentration can then penetrate further into the liner. The liner loses its elasticity, it elongates etc, we've all seen it.
Re: Safe pH levels for vinyl pools
Actually, according to two different engineers -- 10+ years apart -- at Canadian General, the calcium content is mostly irrelevant. But, the swelling at low pH is consistent from all sources.
However, what you are saying about chlorine penetrating is also contradicted by all vinyl engineers I've spoken with -- the consensus I've encountered is that chlorine at pool levels (<100ppm) doesn't affect the vinyl sheeting, but CAN damage the printed patterns, and some dyes, especially medium blue.
Also, the article refers to a study, but doesn't cite it or state when and where it took place nor who conducted it. Nor is there any bio or CV info on "Donald Redpath". The article reads much like one of the "expert" articles from Service Industry News . . . and those aren't entirely trustworthy.
So, unless there's better info, I'm going to stick with the info Chem_Geek and I have been given by vinyl sheet mfg engineers.
Ben