Sequestration or Chelation??

[mbar]

Yes, the ascorbic acid is eating the chlorine. You can start to raise the chlorine to 6, just lower the ph back down to 7.0 - 7.2. You don't have to raise it so slowly when the ph is down. You should be fine - just keep adding chlorine to take it back to 6. As long as the chlroine is still being eaten, you won't get any stains - it won't be high enough long enough to stain You should be ok with the sequesterer. Don't worry so much, I know it's a pain, but you will get the hang of it. If stains do start to come back, just lower the ph and add more sequesterer - it will fade the new stains right away. It is just the embedded ones that need the ascorbic acid. My water temp is 68 too I am hoping to get some more swim season in, but it doesn't look too good - I get really sad when I have to close the pool Keep us posted on your progress.

[Jakebear]

Rather than leave everyone hanging, Here is the end of this saga. The stain is gone and the pool is back to normal.

It took a total of 6 days to bring the chlorine and pH back into range and keep it there without a lot of extra messing around. I have started using the maintenance dose of Metal Free so hopefully this process will not have to be repeated anytime soon (Never will be too early). So far I do not see anything "falling out" so I suppose it has been captured (hopefully forever).

Other than the cool nights and lack of sunshine, swimming might get back into the near future but the weatherman is not cooperating (65 high tomorrow) -- Pool temp is 79 today (my minimum is about 83).

Thanks again for the help and Information. This thread gets printed and filed for future reference.

[mbar]

Glad to hear all is well Don't worry, if you get any stains back next year, you will know how to get rid of them before they become hard to remove. The key is to keep the water balanced with the ph on the low side, and keep up with the chlorine so you don't have to shock very often. Plus keeping the sequesterer in the water at all times. It is the first thing I put in the water when I open in the spring - sequesterer goes in as soon as the cover comes off - then chlorine. Tomorrow I close the pool, I am sad

[Jakebear]

Hello again,

Well, nearly a year has past and the same stain is back. I have used a chelating agent (Metal Free [Natural Chemistry]) religiously. The pool is sparkling and the Chemistry is great (see below), I just don't understand why this stain keeps coming back??

The pool gets cleaned 3 or 4 times a week with the Aquabot (it's never dirty -- mostly the pool gets cleaned -- because ---) so if something would drop out, it would get gobbled up before it could go (dissolve) back into the water.

Since we are full BBB with bleach injection everything has been very stable, and the water has been great. Not even any good reason to shock.

My only thought was that I do not change the DE filter unless there is a back pressure situation and this has only occurred twice since I opened the pool.

Perhaps I need to change to a sequesterant?? What do you think?? Any recommendations??

H2O Temp = 86
FC = 3.6
CC = 0
CYA = 28
Phosphates <50 PPB
pH = 7.6
TA = 90

[mbar]

This is only a theory on my part. I used to get a lot more staining when my cya was under 40. I now keep my cya at 50 or a little higher. One year I experimented with keeping it at about 30 and had a lot of stains, Last year I kept it at about 50 and had very little staining. The lower cya may make the chlorine eat up the sequestering agent faster. I have been using Proteams Metal Magic, and it seems to work really well. If I see any stain starting to form, I add it and it takes it away. I also have been keeping my ph low - not higher than 7.4, with alkalinity no higher than 90. I also used a clarifier that Waterbear reccommended - Seaklear natural clarifier, here is a link: http://www.poolgeek.com/SeaKlear-Nat...ools-p/skq.htm
I am not sure which it is, or the combination of all three, but my pool has not had much staining at all this year after the initial ascorbic acid treatment I had to do at the beginning of the year after opening to a green swamp and having to have my chlorine levels at shock levels for 2 weeks I am working with a friend of mine that has had a lot of pool problems, algae and staining I am going to try using this theory on her pool too. I will keep you informed.

From your water chemistry, everything seems to be in order. I would try to raise the cya up a bit and see if it helps keep the sequestering agent in the water longer. Maybe even try the SeaKlear. I don't think there is much difference between the good sequestering agents. So it is up to you. I do like the Proteam Metal Magic, but I also liked Jack's Magic and Sequasol too. I have heard good things about getting a metal out from Ace Hardware that is cheaper too. I can't remember the name right now. I would suggest taking the ph down and adding the sequestering agent, to see if that will do the trick by itself. If not, a little ascorbic acid will do it - I know it is a pain, but you may not need a lot. I am still experimenting to see what works best, that is why it's great that you let me know works well for you, so we can put them in the "stain eliminator" reference

[Jakebear]

Hi Marie,

Thanks for the reply. I was looking at the Metal Magic web site, this product seems a lot cheaper than the Natural Chemistry. Just wondering, did you use the SeaKlear because the Metal Magic made things cloudy?

I've been procrastinating since things are finally nice and warm and the stain is still "minor" (not visible except the skimmer boxes & not the steps yet) and I don't want to lose a day of swimming right now. Also, I did not see anything about phosphates on the Metal Magic label either. I'm still investigating.

What bugs me is where this is coming from since the K-1716 Iron Kit from Taylor shows 0 ppm, same with copper using the K-1730 kit (0 ppm) (both samples of my make-up water). What else is there? Or better yet how do I test for it?

[waterbear]

All HEDP based seqesterants will cause phosphate levels to rise. Don't worry about the phosphates. It's really a scam. Chitosan based clarifiers (like SeaKlear) have some sequestering abiltiy but not as much as a HEDP based product. The Ace product is O-Ace-Sis Metal Out Plus.