Vinyl staining questions plus other newbie questions

G

Guest

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!!
 
Welcome to TFP!

The stains are almost certainly iron stains. Iron stains can sometimes be removed with sequestrant alone, Sparkle Conquest is a sequestrant. Sequestrants bind to the metals in the water and prevent them from causing stains. The only disadvantage is that sequestrant breaks down slowly over time and needs to be replenished.

The sequestrant almost certainly lowered PH and TA a little, and a few of them will also use up a bit of FC as well.
 
Okay, back again after a few weeks. Here's my question about the staining: What causes it? My pool seemed pretty much perfect, but suddenly (over about 2 days) the staining came back big time! I put in the "maintenance" amount they recommended (4 oz) once or twice since I did the original treatment on August 6.

Here are my readings from a couple of days ago when it seems like the staining really started to come back:

FC = 6.0
CC = 0.0
pH = 7.6
TA = 70
CH = 80
CYA = 40

If I decide to commit to the Conquest regimen (4 oz every 1 weeks), it seems I'll be spending quite a bit of time increasing pH and TA, since it really drove it down after the first treatment (of course that was a whole bottle - 32 oz). Is there some other way to keep the staining in check?

Any ideas, recommendations, etc?

(I have to admit at this point I'm thinking more about when to close up the pool, than I am improving my maintenance procedures. It will be upper 90s, and may hit 100 degrees over the next few days, so Labor day weekend will probably be perfect pool weather. But, since I don't have a heater, I doubt there will be too many really swimming days as we move into September.)

Thanks in advance for your help!
-Dan-
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.