[quote user="Poolguy"] How mach Javel is enough to choc a pool? Well in a 10 x 5, I have been known to use a whole 20 litre drum (9.6%) as I wanted 10PPM to clean up a particularly nasty situation. If its not so bad, maybe half that. Good idea to dilute it 50: 50 before adding, and pour it in away from the liner to avoid repercussions on the liner. [/quote] Hello Andrew I had a pool installed last summer, and the manufacturer states that to keep the warranty valid for the liner, I must use their chemicals - they are non-chlorine based (apparently), and my question is, does chlorine affect liners and if so, at what strength would the ppm have to be to do such damage (fading I guess?)? Jamie