Need help with in-progress ascorbic acid treatment

jimmyz80

Member
Sep 28, 2019
15
El Dorado Hills, CA
Our ~15,000gal plaster pool has mild but very noticeable staining across much of the surface, and some recent testing with vitamin C tablets indicated that this was metal staining. The tablets cleared it right up in an area about 6" around the tablet. So I bought a bunch of supplies and was planning on doing the following:
1. Lower FC to 0 using Leslie's Chlor Reducer which appears to be Sodium Sulfite.
2. Add Polyquat 60 to prevent algae during the low chlorine period. I also have 50ppm borates in my water already.
3. Add ascorbic acid and wait.
4. Add Metal Magic sequestrant.
5. Add a CuLator in case it will help pick up any metals released by the sequestrant over time.
6. Re-balance water.

I completed step 3 about an hour ago. The stains have pretty much disappeared in the area where I distributed the powder (about 2lbs total), and it is noticeably lighter over the rest of the pool. Do I wait longer and hope the other non-contact areas improve? Add more ascorbic acid? Both? Metal Magic also claims to help lift stains so should I go ahead and add it, or wait until the ascorbic acid has done its thing entirely?

Thanks!
 
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Do I wait longer and hope the other non-contact areas improve? Add more ascorbic acid? Both?
Continue. Add more AA around stained areas if you have it. Don't be surprised if you don't pick-up much iron afterwards because it is in suspension and being held by the sequestrant. The most idea way to get rid of the iron is to exchange the water with fresh non-iron water. So if you keep the same water, be prepared to maintain a consistent dose of sequestrant in the future. Best of luck on the AA process. Below is a link for you to refer to as well.

 
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Jimmy,

I completed my first ascorbic acid treatment several months ago. Same procedure you are using except no chlorine reducer. If it were me I would add a little bit more ascorbic acid in the areas you are having problems with as Pat suggested. then wait overnight . My pool look brand new after waiting overnight with no additional ascorbic acid but I do not think it would hurt to add a little more. May want to consider adding polyfill to your skimmer after this step. Metal Magic claims their sequestrant will crystallize the iron into fine particles that can be removed. in my case it did appear that I recovered a lot of tiny dark specks in the polyfill . I think it is too soon to declare success though since I only did this a couple of months ago. My pool looks really fabulous since I completed the process. If I do see any Return of the iron staining I think I would go back to add some sequestrant and then try the CUlater. if that does not work I would do a water Exchange.

I hope this helps and please do keep us posted on your progress.

Chris
 
I left mine alone over night and it removed more stains. I also added more AA and let the water circulate then it says to slowly bring your FC back up. AA neutralizes Chlorine so be prepared to keep adding Liquid over the next week until it catches up
I added slowly and seems like it was 2 weeks ( I used 10 pds in my 28k for bad stains ) before it started leveling out.
Also the metal treatment should keep removing more stains just keep the FC low
Just my 2 cents
 
Thanks for the help everyone. I left it overnight and it did seem to help a bit more, but I can still see the areas where I dropped the vitamin C tablets are noticeably lighter. Yesterday I used up my 1kg bag of AA from Amazon, so I Prime Now'ed an additional 1Lb from Whole Foods and spread that around the pool. Will check it again tomorrow to see if things have improved any more.
 
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I still had some stains and gave up but seems the metal out I used ( It says more is better ) seems to keep pulling stains out. I think one of the tricks is like they mentioned don't go in panic mode and try and get FC back to 8 over night..At least in mine the polyquat kept the algae away :)
 
Quick follow-up question for the group. What's the normal process for bringing the FC back up to normal levels? I started initially by adding enough 10% liquid chlorine to bring the FC up to 2ppm, knowing it would drop rapidly. Checked the next day and it was zero. I've now done that for like four days in a row, so do I keep doing that until it stops dropping to zero, and then slowly keep adding more until I get up to the desired level from the FC/CYA chart? Or should I be doing something more aggressive to get it to stop dropping to zero each night? Water is still 100% crystal clear.
 
If your schedule permits, I think you're going to need to be a little more aggressive by not waiting until the next day to see where the FC is at. Increase it to about 2-3 ppm, watch for staining that may try to reappear, and test again in an hour or two. See how quickly it drops and try to keep it from dropping. Eventually, once you've confirmed the stains do not reappear, you'll get the FC to hold to the minimum FC level and ideally your target value.
 
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Another follow-up question on this process... After adding the Metal Magic, the pool expectedly clouded up for a day or two until the filter cleared it all up. Out of curiosity today, I opened up the filer and cleaned off the cartridges to see if the cloudy junk would come out. Sure enough, it looked like I was hosing milk out of the cartridges for quite awhile. Do any of the chemistry nerds here know definitively what this stuff is? Is it the metal particles bound up with the sequestrant, and if so does cleaning the filter like this mean I'm successfully removing the metal from the water rather than just sequestering it? Or is this milky junk just some other compound generated by the process? Thanks!
 

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Did you add anything to the filter like DE or jacks filter fiber? I used jacks and it kind of looked like that
Nope didn't add anything at all, aside from the chemicals mentioned in my first post. Whatever it is, is weird stuff. Looking at it up close it looks like small white granules but when you press on it, it just feels like gooey slime. Not granular feeling at all.
 
I think setsailsoon had some sort of goo as well when he did his AA treatment.

I have an AA to do as well. But waiting for spring opening day when fc will be zero and water cold enough that no algae can start.
 
Another follow-up question on this process... After adding the Metal Magic, the pool expectedly clouded up for a day or two until the filter cleared it all up. Out of curiosity today, I opened up the filer and cleaned off the cartridges to see if the cloudy junk would come out. Sure enough, it looked like I was hosing milk out of the cartridges for quite awhile. Do any of the chemistry nerds here know definitively what this stuff is? Is it the metal particles bound up with the sequestrant, and if so does cleaning the filter like this mean I'm successfully removing the metal from the water rather than just sequestering it? Or is this milky junk just some other compound generated by the process? Thanks!
According to the Proteam website the MM is supposed to "crystallize" the suspended metals. Perhaps this is what you are seeing.
ProTeam-Metal Magic

Since you just finished this treatment about a month ago how is it holding up?

So I am getting ready to do the same thing on my pool, to get rid of iron that I believe was introduced to the pool from contaminated salt. For you or anyone else that has done this does combining an AA treatment with the MM seem redundant? If the MM treatment removes metals and "crystallizes" it so it can be filtered out, what is the purpose of the AA treatment at the same time? Are there any chem guys that know if the MM pulls the iron from the AA?
 
That MM says it will remove ‘suspended’ metal particles. The results shown above indicate it is a clarifier. I suspect that with an AA treatment you will return the metal to a dissolved state. You could raise the FC level to cause the iron to oxidize, which can be filtered out, but best is to drain the pool and replace with metal free water.
 

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