Iron stains

[Helen203]

Not sure where to post this, but here goes.

After 9 years, our pool was staining. Walls, floor, sunshelf. Iron stains. We followed the TFP protocol as we saw it:

1. Slammed the pool (first time in 9 years!) Took chlorine pretty high in case mustard algae was staining the pool
2. Reduced phosphates bc it was 2000+ (my guess is air pollution in Maryland)
3. Reduced chlorine to 1, pH to 7.2. Took a long time to get chlorine to drift down!
4. Added 1 quart ascorbic acid (15,000 gallon pool)
5. Stains still present but lightened. Added 1 quart citric acid. I know! It was accidental! I thought the bottle was ascorbic!
6. Stains lifting but still visible
7. 24 hours later, chl = 0, pH < 7
8. Added sequestrant recommended by tfp. Remaining stains lifting.
9. At noon, started correcting pH to 7.2.
10. At 2pm, started reintroducing chlorine at 1 quart per hour. Stopped when we hit 2.

We would never have attempted this without TFP. Thank you so much!!

 

[Texas Splash]

 

[Texas Splash]

Now remember for next year, the iron is still there, bound by the sequestrant, until you change water - or enough of it to lower the iron level as to not be effected by the pH or FC. During times when the cover may be off, fresh water from rain & snow might help, but you may also need to consider using polyfill next season if the iron comes back. If it does, visit us next season and let us know. We'll walk you through other steps to take.

 

[Mdragger88]

Helen, glad it’s going well.
In the future if you attempt the AA treatment again be sure to use some polyquat 60 algeacide before letting fc fall as described in the AA article.
It buys you the 24-48 hours needed to prevent algae whilst you do the stain removal at low fc levels.
While you do need to increase fc slowly be sure to get above minimum for your cya to prevent algae. As a slam may make the stains reappear. Keeping ph lowish for a while is key.

Ascorbic Acid Treatment - Further Reading

www.troublefreepool.com

 

[Helen203]

Something has gone wrong —pool is “milky”. AM chlorine reading was 1.5 (added 2 cups chl) PH 7.2, everything else in range. Afternoon pH and chl readings were same. Only difference is we started the SW generator about 2 hours ago. The robot is fuzzy, can’t see bottom drains at all. …no chloramines both tests. Also, our CYA is somewhere between 30-40.

 

[Texas Splash]

I hope algae didn't already start with that low FC level. In your post above you said nothing about using Polyquat 60 algaecide to prevent algae. Did you use any?

You may want to do an Overnight Chlorine Loss Test.

 

[Helen203]

Did not add an algicide. I moved FC to 3 this morning with chlorox and have the swg running at 30%. Other than chlorine, everything is holding steady. Update: it is solid material like dust — we realized this when we brushed the pool. I think the filters should pick it up eventually!

 

[Texas Splash]

with chlorox

That could part of the issue. The Clorox brand bleach has fabric additives that tend to disrupt pool water chemistry. I would stop using Clorox and substitute it with another brand of bleach or use pool chlorine.

 

[Helen203]

Oh, its 10% chlorine from Home Depot, I shouldn't have been so imprecise on this forum

 

[Mdragger88]

What sequestrant did you use?

 

[Mdragger88]

It should be fine at this point to maintain target fc levels just increase slowly.
Definitely Do an
Overnight Chlorine Loss Test at target fc levels.

 

[Helen203]

Sequestrant: Pro Team Metal Magic

Pool is crystal clear this morning after running 24 hours on low.

We will be sure to pass the overnight chlorine test before we close the pool in a few weeks. I read it can take a week or more to clear the ascorbic and citric acids we used.

 

[Mdragger88]

The Metal Magic mentions that large doses (such as the initial dose) can cause temporary cloudiness especially if ch or tds is high (salt pools can fall into this category as salt is a dissolved solid)
or csi is positive. Glad it’s clearing up for you.
Don’t forget to do the monthly maintenance doses until you can get rid of the iron laden water or the iron will show itself again.

 

[Mdragger88]

**The jury is still out on whether the MM can actually do what it says (form crystals which allow you to catch the metals with your filter) some have reported some success as evidenced when they cleaned the filter others haven’t noticed a difference.
I am in the camp that I need a sequestrant regardless and MM checks all the appropriate boxes for me (HEDP, smallish required doses, monthly maintenance doses vs weekly, & fairly affordable)
so if it happens to do this miraculous thing it claims- even a little- I ain’t mad at it I just wouldn’t bank on it.

 

[Helen203]

After dealing with high phosphates and iron…i think we will close the pool as we always do, follow-up iron treatment in spring as needed, drain and refill. Water is cheap here bc we have a septic system and don't have to pay the WWTP surcharges.