Dave,
We have only lived here 3.5 yrs...and the pool guy est the liner to be about 7 years old. Unfortunately I do not have any numbers just yet b/c the water is not completely in (they ran into a problem w/one of the light fixtures yesterday), so we had to stop filling it.

I really do not know what could have caused it to tear...it started where there is direct sunlight during most of the day. We do have pine and evergreens around it, but that part of the deep end gets the heat of the day sun for about 4-5 hours. The Aqua Chem Granuals we have now is a Trichloro-s-triazinetrione (71.8%), Boron Sodium Oxide - Pentalydrate 8%, and the other ingredients (Clarifier, filtration enhancer, sunlight protector 20.2%).

We checked directly with Tara Liners (warranty dept), and he just called me back and said in the mean time to just use what we have-but keep on top of the alkalinity and PH(obviously) _ I am always checking the levels daily anyway...He said once we are thru these 2 buckets (22.5lb each) we should switch over to Dichlor...

He said typically vinyl liners will last 7-10 yrs. SO much for the 20 yr warranty we thought we were getting!

Thanks again for any help !!
Dina