Used vitamin C, still some rust marks

May 30, 2009
1
I used the vitamin C on my fiberglass pool; the stain is gone around the rim of the pool. There are some rust marks on the steps. I've read you should use metal out after the vitamin C application. Will the metal out help with the stain on the steps? Also, what is an sequestering agent is. Thanks for any feedback.
 
Are the stains small enough that you could rub a crushed vit c tablet on the stains directly?

A sequesterant keeps the metals "in suspension" - by removing them from the pool surface, they are now in your water, and without a sequesterant, they'll just redeposit in the pool surface again. Sequesterants require routine maintenance doses.

Can you post a full set of test results? Perhaps there are clues that could help prevent the stains from returning.
 
Last year, I bought a bottle of big tablets of vitamin C.

I had a few rust stains, and I would just set the tablets on top of the stain, until it dissolved away. For some stains, I had to do this a few times, but eventually, the stains went away.

Rubbing the vitamin C into the stain didn't work for me, and it was easier just to let a tablet sit on top of the stain, and dissolve.

Randy
 
Here is the full procedure
ascorbic-treatment-to-rid-pool-of-metal-stains-t2298.html
Sequesterant are often sold as metal removers or metal treatments. They don't remove anything from the water, just chemically deactivate it and have to be reapplied on a regular basis. Look for ones that contain HEDP, Phosphonic acid derivatives, or Phosphonates (different names for the same thing) and avoid the ones that contain EDTA. Good ones are Proteam Metal Magic, Jack's Magic Pink Stuff, Sequa Sol, and many of the less expensive house brands (such as the O Ace Sis brand from Ace hardware).
 
I would try to remove the rust stains with a Mr. Clean magic eraser first. I usually don't bother with ascorbic acid with rust stains, because it messes with the chemistry of the water too much. If you only have rust stains, and not an all over pool stain, it is not worth doing the ascorbic acid - it is expensive and time consuming. Let us know how you get rid of the stains - it is always good to have people's input :)
 
Thanks Waterbear! I don't really read the forum too much, busy with grand babies :-D , but I will answer any questions about staining - just pm :) Hope you are having a great start to summer everyone! By the way I used citric acid this year instead of ascorbic cause it really got expensive, and so far it worked like a charm. :mrgreen:
 
mbar said:
Thanks Waterbear! I don't really read the forum too much, busy with grand babies :-D , but I will answer any questions about staining - just pm :) Hope you are having a great start to summer everyone! By the way I used citric acid this year instead of ascorbic cause it really got expensive, and so far it worked like a charm. :mrgreen:
yep, one of the pool suppliers for commecial pools in my area sells citric acid in bulk for stain removal! It works about the same as ascorbic acid.
 
Hey mbar,

you may have seen the earlier thread on my chronic stain problem. I did the full vitamin C treatment and have been following up daily with sequestrants. So far the pool looks good except for the very bottom and sides in the deep end still have some staining. Do you suppose the magic eraser would help with any type of metal stains?

I might rig something up on my pole with a magic eraser and see if that works. It's not just a spot or two, but pretty much the entire end of the pool where the stains reside.
 

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Are you sure it is a metal stain? If the ascorbic acid does not take the stain away, it may be organic. When you did the stain treatment did it all go away the first time, or was there some stian left? If it is metal, and a big area then I think that using the Magic Eraser would be too much work :( Have you tried any citric acid? I think you may need a little more stain remover. You can get citric acid cheaper than ascorbic, and it works just as well. When you put it in, let the filter on circulate overnight, if the stain is not gone, but has lightened then add more citric acid and continue to recirculate for a couple of hours more. You want to remove all of the stain before you start to rebalance the water again. Don't forget to add more sequestering agent if you are removing more stain. You can order citric acid at this site:

http://www.chemistrystore.com/search.cg ... earch2.y=0

I know it's a pain to do stain treatment, but if you get it all, and keep up with the sequestering agent, you should be stain free all summer. If you see stain start to come back, add more sequestering agent while keeping the ph at 7 - 7.2 and it should take the new stain away. Feel free to ask any other questions you have :-D
 
Thanks, mbar.

I've just completed doing the full ascorbic acid treatment linked on this forum. I've kept my PH around 7.2 and have added sequestrant daily. I actually did this last year too, but not as thorough with continued sequestrant treatment.

The more I look at this, I believe the stain in the deep end of the pool is where the staining begins and slowing spreads over time. It was hard to tell if it was completely removed the first time I did the treatment, but I'm very doubtful that it was-I think it is just getting worse again, despite the fact I'm adding sequestrant every day.
My other thought is that this area is mostly an older copper stain that has never fully gone away. I have very high copper levels in my water, thanks to a heat exchanger that corroded and had to be replaced last year.

I'm doing a lot of partial drains and fills, and the rain has helped. I'm also working on getting my CYA down, so chlorine isn't so hard to manage. Then, I can consider another vitamin c treatment. I went through 4ea 128oz jugs of 10% chlorine since I started the stain treatment last week. It's still not quite holding.

I think a lower CYA would solve a lot of problems and mine is getting there. It was 150 last year. I've got it down to around 68 now. Hooray!
 
Wow. Good prices on Citric Acid

How does citric acid use compare to ascorbic acid? I would guess that I would need more citric acid to get the same results as Ascorbic?
 
Yes, the citric acid does take a little more, but it is so much cheaper. The stain doesn't disappear quite as quickly as with the ascorbic acid, but after being on recirculate for 2 hours you can tell if you need more. I also found it easier to rebalance my water after the citric acid this year - but it's always hard to say, because the water never acts the same 2 x in a row :roll: So far I have not gotten any stain back - but I did put a lot of sequestering agent in and have been keeping up with it every week. Keeping your cya where it is even is a lot better than when it was! You don't want it too low, cause the sun burns off the chlorine too fast and then if it goes down to 0 you often will get the start of an algae bloom, which means shocking and then maybe stain :hammer: It can be an endless cycle. Once all of the stain is gone and you get the water balanced, keep up with the chemistry (chlorine & seqestering agent, keep the ph 7.0 - 7.2) and you should be fine. :cheers:
 
Just out of curiosity, how much sequestering agent did you use during your stain problems?
I'm afraid to go even 1-day without adding at least 4 ounces.

I've gone through more than two bottles if it in the last two weeks, and haven't even swam in the pool yet. I'm going to cutback and just keep a really close eye on the stains.

I wonder if changing the sand in the filter is a good idea for folks like us who've battled stain problems?
 
My pool is 16 1/2 ,000 gal., and I used about 4 bottles of sequestering agent and about 5lbs of citric acid. After the stain treatment (three weeks ago) I have added about 4oz. of sequestering agent a week. I also used alagacide. My numbers are:

FC - 4
CC- 0
PH- 7.2
Alk- 80
Cal- 200
CYA- 30 - 40

My calcium was 250 before the stain treatment - so it dropped about 50 - I don't know why.
So far I am not getting any stain, however I did use a lot of chlorine (bleach) to get the pool balanced.
I do have a lot of trees, a lot of caterpillars this year, so I know it was a heavy chlorine load. Even when I kept the water at shock, no new stains appeared :goodjob:
Now my water is holding everything even. However, we will see what happens next week, you never know :wink:
 
Your numbers are very close to mine, except for the CYA.
Despite all the struggles, I'm so much better off than a year ago.

Two years ago when we bought the house we used a pool guy - and I was completely naive. The pool looked beautiful every week, but little did I know he was destroying my heat exchanger and raising my CYA levels by putting trichlor pucks in the skimmer. I also had very high TA levels when I took over the chemicals.
 
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