Ascorbic acid treatment

Hi I am new to forum and I have a question about the ascorbic acid treatment.
I have a 15K fiberglass pool that had yellowish/brown staining on the walls when I opened this spring. I had to fill my pool with public water, it was 50% empty. I then took a water sample to local pool store and balanced water according to their instructions.
I then proceeded with 5 AA acid treatments. This is what happens. I do the AA treatment, water clears on day 1, by day 2 water is very cloudy, day 5-7 water still cloudy and stain returns.
I have had my water tested for metals and it is negative.
I have a sand filter that I had sand changed in thinking what ever was staining my pool was trapped in the sand.
I also have a heater which I have not used because I have not had a chlorine reading in my pool since I opened it, despite having trichlor tabs in the skimmer.
I have 4 pucks in the skimmer 5 days post 5th AA treatment and still no chlorine registering and stain is slowly returning.
My main question is why is this stain coming back? I have had my water tested by 3 different companies and every one here is stumped. They say everything is balance perfectly, and their are NO METALS in the water. They have no idea why the stains keep coming back after the AA treament.
I am so frustrated and have spent hundreds of dollars in chemicals trying to get rid of this stain. I can not find anyone to help me locally. Everyone is stumped. Please help!!!

Hi and welcome to the Pool Forum!

Instead of just saying "balanced perfectly," we need to see actual current water testing numbers taken with a drops-based kit to be able to help you. In particular, I am wondering about your pH level since you have a heater.

Do you have a test kit? If so, what kind?

Please take a couple of minutes and fill out our pool chart. it will make it easier for someone here to help you.

Pool Chart Entry Form
Pool Chart Results

Also, please tell us exactly what all you have added to the pool -- meaning ingredients and not just product names or 'shock.'

Thanks for responding. I did fill out the pool chart and saw it on the chart results.
I only have the test strips not a drops-based kit. According to my strips:
pH 7.2
Free Cl 0
Alk 80
CYA 30-50
I do have heater, but have not actually heated pool, due to the fact that I have had free chlorine readings of 0 and afraid of an algae bloom.

I added on 6/22 2lbs of ascorbic acid and 1 liter of Metal Free 1 hr later, and I removed my trichlor from the skimmer. I then let my pump run (I had on filter not circulate) for 24 hrs. After the 24 hrs I ran my aquabot robotic cleaner, backwashed the filter, and put in 2 trichlor tabs in the skimmer. PH and all has remained as seen above. I never saw a drop in ph or alkalinity after the ascorbic acid. I stopped running pump 24/7 and went back to 12 hrs on/off. The stain was gone and pool was crystal clear. Then on sunday, it was milky cloudy. Still had no reading on free chlorine, so I added another puck for total of 3 3" pucks in skimmer. Monday was even cloudier and added another puck for total of 4 and 4 oz of proteam severest algae treatment. Now it is wednesday and still cloudy and no free chlorine (despite 4 pucks in skimmer) and now I am noticing the stain returning right under the water line.
I have hired a professional to try and help me with all this (have maintained on my own with no problems past 4 summers). But as mentioned earlier, no one here has any clue as to what is going on! He changed the sand in my filter thinking the sand was holding the organic which was causing stain. But that does not seemed to have helped.
Thanks for your help! I have spent $$ in chemicals to no avail and I am ready to close my pool!!!

Hi TLM;

Metal removal is NOT something you can accomplish in a haphazard fashion. Reading your post, I realized I'd made one big omission in the Ascorbic acid guide: you MUST have a K-2006 BEFORE you start. I just finished editing the guide to add that.

Metal Free is not helpful. Don't waste any more money on it.

If you want REMOVE the metals from your pool, you probably should also stop ADDING them. Your Proteam algae treatment, according to Proteam claims has

Quote:

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Higher copper content than other competitive brands

---

Probably what you should do, right now, is read the guide, and then
1. Order a K-2006.
2. Lower your pH to ~7.0.
3. Get some HEDP and add it.
4. Get some polyquat, and add it, so you can keep your chlorine low.
5. Meanwhile, add bleach 3x per day VIA the skimmer at the rate of 1/2 gallon per dose. Remove ALL trichlor tabs from EVERYWHERE, before adding bleach.
6. Run your filter 24/7.
7. Do the metals bucket test on your FILL water.
8. Give us test K-2006 test results on your POOL and your FILL water, plus bucket test results on your fill water.

Thank you! I printed everything out so I can follow very closely.
I did these treatments according to what the local pool companies have told me to do. But obviously, they have no idea what they are doing or talking about!!!

Want to repeat the steps to make sure I am doing them right.
Get k-2006 then:
1. Lower my ph to 7.0
2. Get HEDP and add it?
Do I add HEDP now or just have it for when I do the AA treatment?
(already purchase polyquat 60 from browsing this forum)
3. Remove trichlor tabs
4. Get liquid bleach and add 3X/day via skimmer at 1/2 gallon per dose
Is this household bleach or something I get from pool store?
How many days do I keep adding the liquid bleach?
I have 3 kids, is it safe for them to swim during this time?
5. Run filter 24/7
6. Do metals bucket test on fill water
7. Do K-2006 test on pool and fill water
8. Report to you on the results of bucket test, and both k-2006 tests
I think I have it right. I am going to get the k-2006 and will report to you the results, may take a few days.
Thank you so much!! Thanks for the links to products on amazon also! Wow what a difference in price!! Should have come to you guys first!!

+ You can add the HEDP now. It will help prevent further stains, might remove some existing stains, and will keep the metal in the water once the ascorbic acid breaks down (which it will as soon as you begin adding chlorine again).

+ Plain 6% household bleach.

+ Zero chlorine is NOT safe; any chlorine level up to 50 ppm is safe for kids, but above 10 ppm may not be safe for swimwear if your stabilizer level is low.

What is your opinion on sand filters? I was wondering if it would help to either add DE to my sand filter or switch to a DE filter?

I have a fiberglass pool, sand filter and have well water. I have learned how to keep my pool stain free. The first thing is to have a good test kit so that you can do your own testing so that it will be consistent. You want to remember that high ph along with high chlorine will let any metals in the water fall out of solution and stain the pool surface. Hedp is your friend. You want to make sure you always have good chlorine levels so you don't get algae so you don't have to shock. Once the stains are on the pool, and the Hedp ( sequestering agent) does not lift them, it is tme for an ascorbic acid treatment. You should never start an ascorbic acid treatment if there is any chance you have algae- because you will just be wasting your time and money. When doing a treatment you will need to have lots of bleach on hand, and borax. I am really surprised that your ph did not go down, it must have been really high. You cannot do just ascorbic acid without the sequestering agent because the ascorbic acid will lift the stains but there would not be anything to keep the metals in solution, and the pool will stain as soon as you get the chlorine & ph high. The ascorbic acid is not dangerous to swim in, but you only want to swim once the water is holding chlorine so that you are sure the water is sanitized. I think you were starting on an algae boom, that is why your water was cloudy. Ascorbic acid eats up the chlorine really fast until it is all gone. Just keeping pucks in the skimmer is not enough. You need to test the water all the time adding enough bleach to bring your level up to your minimum level according to your cya. Hence needing a good test kit! Don't get overwhelmed, it is not hard once you know what to do, and we will help you! let me know if you have any questions,