First, I must say how incredibly helpful this website has been. We bought this house June 2010 with a IG vinyl pool that hadn't been touched in 4 to 5 years. We actually didn't pay much attention to the pool since we did so much ($$$) to rehab this house (it was a short sale), and were a flip-of-the-coin away from filling it in.
Last summer was a bit of a roller coaster, but we did get it swimmable. And with the help of Trouble Free Pool this summer has been great. We've been in St. Louis 11 years now and have decided that the only way to enjoy (nay, survive!) these 100+ degree summers is to have a pool. We are LOVING it!!
This summer I bought a good test kit (see signature below) and have been successfully managing the chemicals, etc. I still have a tub of 3" tablets I'm using for day-to-day chlorine, but use bleach, borax, and baking soda regularly to handle shocking and balancing ph, etc. Many thanks to this website for teaching me how to do that!
My wife has been bugging me recently with "why is the vinyl looking so discolored recently?" It's supposed to be white, but has been looking pretty "tan" lately. My response was, "it's always been that color, it's just with the regular/good chemicals it's now getting, some spots are getting stained white so you think the rest is stained. What's actually happening is that you're just now noticing the stained regions." Well, of course, my wife was right.
I mentioned this at the pool store yesterday and they said I should add some Sparkle Conquest. I wasn't happy about spending the $30, but did. I added it to the pool last night and today the vinyl is pure white!! I am delighted - even if I had to eat a little crow. (I'm stunned at how effective it is, and how terrific the pool looks today.)
So my question is related to why this staining occurs and if I can avoid it in the future. Mind you, the maintenance instructions say I should only need to add 4 oz every 2 weeks. But I'd like to know if there's some aspect of my chemical balance that I should be especially watching to avoid this staining.
Here are my readings from tonight - please note my readings for everything are a little low tonight (highly unusual). The FC and pH in particular are abnormally low (hello borax & bleach!). Maybe it's the Conquest? At any rate, I noted below my usual readings (I've been keeping a very good log this summer).
FC - 2.0 (usually around 6.0)
CC- .5 (pretty normal)
pH - 7.0 (usually around 7.4, a tad low but the pool seems to like it there!)
TA - 50 (usually around 70)
CH - 70 (usually 80 or 90)
CYA - 30 (usually 40 to 50)
That's my story. Again, thanks a million for a great website!!