AA Treatment - weird results

[delaneybob]

Hi,
I am doing my second annual stain removal with AA and got weird result.
Only difference this year is I used Hydrogen peroxide to lower Chlorine. I used 32oz of 12% H2O2 to lower 4.5ppm Cl to zero (2 x 16 oz treatments before starting)

SWG is off

At start Cl=0 and PH was 7.0. Added algaecide and then added 1 lb AA. No real results so I upped the AA another 1 lb. Still no big difference (my staining is light) so I decided to recover the pool. I added Baking soda and borax to recover the Ph to 7.0-7.2. TA is 40ppm- staying on low side since I was trying to not experience alot of acid adds in the summer to control PH

I started with stabilizer as CYA went to zero (not sure why) and got it to 40ppm. Cl=0 and PH was 7.0.

Then I added 2 gallons of liquid bleach to start to raise chlorine levels figuring the AA would eat most of it. Previously (last year) it took a ton of bleach to neutralize the AA.

Well, the Chlorine levels on FAS was 6ppm and the PH pegged purple indicating high chlorine levels. This was confirmed on both the easy 5 drops easy test kit and the more official K-2005 and FAS

So I added Muric acid to being down PH and letting things stabilize

VSP is running 24/7 at 2000rpm for the AA treatment

I don't get why Chlorine would be so high after 2 gallons of bleach nor why PH would skyrocket

Any ideas?

 

[delaneybob]

PH is 7.2 and Chlorine is 4 ppm FAS. I should have to add like 10-13 gallons of bleach to get rid of the AA and get chorine to hold. Its almost as if I never added the 2 lbs of AA

Pool temp is 65F that is also a difference than last year when I did it when it was in Spring- pool temp likely 75F

on the Peroxide add to get rid of Choline for AA prep, I found a calculator that figured it out and backed off- turns out it was pretty close- can't find it at moment but don't think its in this forum

 

[ajw22]

Sounds like the AA you got was a dud. Where did you get it from?

 

[delaneybob]

Amazon- same place as before. In fact the first 1lb was from last years (left over)

 

[Mdragger88]

Are you sure you’re stains are from iron? Are they leftover stains from the previous treatment or new?
Them being a different metal doesn’t explain the fc thing though
Got anything removeable that’s stained you could test the aa on in a bucket? (If you have any left)
Barring that you can just try a different vendor- duda diesel sells AA on amazon & i have always been happy with their other products.
I am planning to do my own aa treatment in the spring so I will be following along!

 

[mas985]

I recently did an AA treatment and my pool water was at 52F. I treated the spa first and it cleaned up right away but the pool took longer. My thought was the lower water temperature took longer than normal for the AA to fully dissolve and reach all of the surfaces. Although where it fell, cleaned up pretty quickly. I left it in for a couple of days since I didn't need to worry about algae and eventually, everything cleared up.

I used this:

Amazon.com

www.amazon.com

 

[delaneybob]

Ok thanks- I will regroup and try a different vendor AA. On the iron stains- yes I did tablet test on steps and have that stain remover on pole thing for spot treatment as well.

I just ordered this
As it will get here today. Will repost after AA treatment but things missing from this forums AA treatment

1. How to lower Cl to zero with a calculator for Peroxide
2. Any affect on CYA (if its expected or not)

 

[delaneybob]

I recently did an AA treatment and my pool water was at 52F. I treated the spa first and it cleaned up right away but the pool took longer. My thought was the lower water temperature took longer than normal for the AA to fully dissolve and reach all of the surfaces. Although where it fell, cleaned up pretty quickly. I left it in for a couple of days since I didn't need to worry about algae and eventually, everything cleared up.

I used this:

Amazon.com

www.amazon.com

Thanks- much appreciated but I already ordered the new AA

 

[delaneybob]

I just put in 2 lbs of AA (I ordered the one mas965 said Amazon.com as the one I ordered got back ordered)
Cl=0 and PH =7.1
only difference is I did not use Peroxide to lower Cl. Cl was slowly coming down (I assume due to bad batch of AA that had some kick to it)- running for 24 hours and will see by this evening as my staining is light

 

[delaneybob]

Pool stains slowly lifting. It must be the pool temp (60-65F). I will let it run but I do not have algae forming (used alot of algeacide on first attempt)- I will start pool recovery tomorrow evening/Friday morning

 

[delaneybob]

So alot better on the AA - I am suspecting the peroxide to be the culprit on the first go around. Pool is at PH=7 and pool temp is at 60F.
I looked at this thread and will start to bring Cl back up despite the AA working slower than last year. Last year was in Spring or Fall and the Polaris bag started to get algae on Day 2 of AA and the pool cleared alot faster. So I am concluding AA in winter (I am in North Florida) maybe better because I may be able (TBD still) to get away with AA without a SLAM afterwards but it will take longer due to lower pool temp (lower reaction rate I assume)

 

[delaneybob]

Ok here are the results
I put 2 gallons on bleach in (over 6 hours) and brought Free Cl to 5ppm FAS using the 10ml method. I know that normally about 20 oz of 7.5% bleach raises my pool 1ppm. This morning Free Cl =5ppm Ph=7, TA=40, CYA=80. I overshot CYA more than I would like but used the pantyhose method in the skimmer for CYA and it worked alot better than previous methods I have tried.

I will not turn on the SWG and wait to raise PH a bit as I will do the 25 ml test FAS (where every drop is 0.1 CL) this evening as I fully expected this mornings Cl test to be close to 0ppm. Now I get to take back a bunch of bleach to the store too .

Overall the stains did not lift fast like it did last year when the pool was at least 10 degrees warmer but results are satisfactory and I will always now do AA in the winter. I don't think Peroxide will be my first choice to lower CL but not sure of an alternate method in the winter. I still blame Peroxide for my first results (very little stain removal and invalid PH tests even though Cl was not very high) . However, I would do it the same way next year rather than do AA in the spring/fall and dump a ton of bleach in and then likely SLAM. Last time it took me 3-4 weeks to find and get rid of that pesky algae.

 

[Mdragger88]

You don’t “need” to use peroxide to lower fc to zero - it just may take more AA if fc isn’t zero.
Not sure if your type of experience is why the use of peroxide is not mentioned in the article. The two things may be completely unrelated.
Just Add your polyquat 60 before letting the fc fall below minimum.
If the pool temp is 60 or below it should buy you the several days you need to accomplish the AA treatment without algae happening.
I don’t see you mention adding a sequesterant. It is imperative that you do or the stains will return.

 

[mas985]

When I did an AA treatment recently, the water was between 52F-55F and I just let FC drop on it's own over several weeks and after adding AA, I drained the pool after several days (high CH too) and never saw any algae. Didn't add any PQ either. Although, I know FL is different than CA in terms of algae.

 

[delaneybob]

You don’t “need” to use peroxide to lower fc to zero - it just may take more AA if fc isn’t zero.
Not sure if your type of experience is why the use of peroxide is not mentioned in the article. The two things may be completely unrelated.
Just Add your polyquat 60 before letting the fc fall below minimum.
If the pool temp is 60 or below it should buy you the several days you need to accomplish the AA treatment without algae happening.
I don’t see you mention adding a sequesterant. It is imperative that you do or the stains will return.

Thanks for the peroxide tip and will use more AA next time.
Sorry about not mentioning the sequestrant, I added 32 oz Pro team metal magic on initial run after 12 hours of AA- same for second. This morning I removed cartridge and cleaned it.
Once pool stabilizes, I will replace the cartridge and add a new CU-L-ATOR in the basket. I typically do not do a Maintenace dose of sequestrant as my pool needs minimal water adds due to rain

 

[Mdragger88]

Thanks for the peroxide tip and will use more AA next time.
Sorry about not mentioning the sequestrant, I added 32 oz Pro team metal magic on initial run after 12 hours of AA- same for second. This morning I removed cartridge and cleaned it.
Once pool stabilizes, I will replace the cartridge and add a new CU-L-ATOR in the basket. I typically do not do a Maintenace dose of sequestrant as my pool needs minimal water adds due to rain

Be aware that the sequestrant simply wears off with or without dilution. If your fill water is what gave you the metals in the first place & you are mostly filling with rain water you should eventually eliminate the need for maintenance sequesterant but that can take a very long time- until then you may want to keep a bit in the water. It may prevent you from having to do the AA every year. Unfortunately its a dance

 

[delaneybob]

Yes thank you. I tried the cu-lator last year to try to help that and it appeared to work as most of my staining was from the previous AA and having to SLAM over long period. The ultra high Cl combined with PH that kept going up rapidly cause some metals to re precipitate during the SLAM. I just could not stomach another AA treatment and go thru all that cost of bleach and time/effort again so soon. High PH creep is also why I have steered clear of alot of baking soda this time and opted for Borax and keeping TA around 40 vs 80 or so.

So this year I will keep Cu-La-tor, even though it has mixed reviews here, On using maintenance doses of sequestrant, the directions on Pro team Metal magic want PH at or above 7.5 and CL ideally at or below 1ppm- the latter ain't happening, especially during the warmer months. I have not added Sequestrant when Chlorine has been in the pool- be infested to hear if other folks had good results with Chlorine in the pool. I have also not used sequestrant when PH was at or above 7.5 as I typically used it after AA when PH was 7-7.2 .

Pro Magic recommends 32 oz per 10,000 gallons- my pool is only 8800 gallons so over 7 days I had 64oz of sequestrant in there. I will watch it and see if staining comes back before march as the pool will still be 60F for a relatively inexpensive and easy cold water AA treatment

 

[JamesW]

If you overdose on peroxide, the left over peroxide will neutralize the ascorbic acid.

You have to use the exact right amount to lower the chlorine to zero and not use any extra.

 

[delaneybob]

If you overdose on peroxide, the left over peroxide will neutralize the ascorbic acid.

You have to use the exact right amount to lower the chlorine to zero and not use any extra.

Thanks. Jst realize there is no calculator here for peroxide other than here and I did it in 2 increments and appeared to calculate correctly for my pool
"27% hydrogen peroxide at a reasonable price of $17 per gallon. It would only take 115 fluid ounces (around 3-1/2 quarts so somewhat less than one gallon) to lower the chlorine by 50 ppm in 10,000 gallons."
My Math- 32/115 ounces x 12%/27%x 8800/10,000 =.099 x50ppm=4.9 ppm Chlorine removed and I saw that was pretty spot on

 

[JamesW]

To check for leftover peroxide, you can do a CC test as the peroxide will register as CCs.

For example, 5 CCs of peroxide will neutralize the same amount of AA as 5 ppm of chlorine.