Ascorbic acid treatment for stains, which sequestering agent to use?

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Amazon
Many of these chemicals will be available locally . . . but the problem is, you probably won't be able to tell. Pool chemical companies put a lot of effort into hiding what's actually in their products. I had to work pretty hard to make SURE that these chemicals were what we needed. I've tried to indicate the products that you may find -- and identify correctly -- locally. However, if you can find the Kem-Tek brand locally, and find IDENTICAL products, they should be the same locally as on Amazon.

1. Kem-Tek 60% polyquat => $18
0.7 ppm per fluid oz; 4 ppm dose = ~ 1 cup liquid measure.
Polyquat is available locally, but this is a pretty good price.

2. KemTek 20% HEDP "Metal & Calcium Eliminator " => $14 (but, get 2 bottles = $28)
0.2 ppm per fluid oz; 2 ppm dose = 1.5 cups fluid measure
It's very difficult to identify the concentration of HEDP products.

3. Photographers' Formulary Sodium Thiosulfate, 1lb => $7
1/3 lb should remove 5 ppm of chlorine from your pool.

4. Ascorbic acid => $17 (but, get 2 pounds = $34)

5. CuLator, 1.5 ppm => $40 (does NOT ship from Amazon)
CuLator, 5 ppm => $70 (does NOT ship from Amazon)
Your choice on which one to buy. If they work as advertised, the smaller one should be sufficient.

6. In the Swim 24 x 1# Cal Hypo => $64 ($2.67/lb) (does NOT ship from Amazon)

Optional:
7. Iron Out, 30 oz => $10, delivered. Does NOT ship from Amazon. Small bottles are probably available locally.


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Local:

8. (5) boxes of 20 Mule Team Borax => Walmart

9. (2) gallons of muriatic acid => Lowes, Home Depot, Ace Hardware

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Testkits

You will need either the K2006 (preferred) or the K1000 for this process. If you don't have either, check this page:
How-to-Get-the-Right-Testkits-for-your-Pool
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PF => 16

OK. Here's the process:

1. Lower the pH to 7.0 using muriatic acid.
2. Clean your filter. Leave cartridge OUT of filter; leave pump on 24/7!
3. Test the chlorine; add sodium thiosulfate to remove it => approximately 2 tablespoons per ppm of chlorine.
4. Add polyquat, 1 hour after adding the thiosulfate
5. Add 1# ascorbic acid.
6. Check pH; add acid as needed to maintain pH at 7.0 or a little below.
7. Brush stained areas every 4 - 8 hours.
8. OPTIONAL: After 24 hours, if stains are not completely removed, put 1/2 of ascorbic acid in a freezer bag, fill it with enough water to make a slurry, and enter the pool with googles and the bag. Continue with 2nd 1/2# if needed.
9. OPTIONAL: Holding the bag underwater, 'drizzle' the slurry onto resistant stain areas.
10. OPTIONAL: Wait 24 hours more (continue to keep pH down). If stains remain, make an similar slurry with Iron Out, and try again.
11. Add HEDP dose; wait 4 hours
12. Replace cartridge in filter; continue to keep pH low.
13. Begin adding plain 6% household bleach, 1/2 gallon every 2-4 hours, till you have a measurable chlorine level. Try not to exceed 5 ppm.
14. Place CuLator baggie in skimmer.

Notes:

• With your alkalinity as high as it is, your pool's pH is likely to want to rise. Be diligent about keeping the pH below 7.2.
• Once you begin this process, leave your pump on 24/7 for the next month.
• Adjust your pool return eyeballs so the return stream(s) is/are NOT directed against any pool surface.
• Once you have the CuLator in the basket, you can gradually begin bringing the FC level up to what it should be -- 5 - 10 ppm, given your CYA level.
• Once you have a FC level of 2 ppm or higher, you can resume swimming.
• Once the chlorine level is normal, use borax, 1/2 box at a time, to raise your pH to 7.6 - 7.8.
• Once your pH reaches that level, switch from bleach to the cal hypo. (instructions below)
• Watch your filter pressure: once you switch to cal hypo, you may find that your pressure builds up quickly. This is GOOD -- but you'll need to clean the filter every time the pressure goes up by 7 - 10 pounds.
• You can dose your pool to 10 ppm FC, and let it drift down to 5 ppm before adding more.
• Using the CuLator *and* cal hypo added in the manner described is sort of a 'belt & suspenders' approach. Hopefully, the CuLator will work as well as advertised. But if not, the cal hypo slurry on your filter will ALSO tend to trap any metals in the water, and when you clean your filter, these metals will be removed from the pool.

To add the cal hypo:

• Remove the CuLator baggie from the skimmer.
• Make SURE there are no other chemicals in the skimmer.
• With the pump running, add the cal hypo (1/2lb per dose) directly to the skimmer, with the pump running.
• A single 1/2 lb dose should add about 5 ppm FC.
• After all the cal hypo is gone from the skimmer, replace the CuLator baggie

Thank you for the prescription, Doc! I have the Taylor 2006 kit and I will start ordering chemicals, but before I do lemme ask: with my high calcium level, will adding cal hypo cause any problems? It is my understanding cal hypo adds calcium, and my level is currently 600ppm and rising weekly due to desert evaporation and high fill water calcium.

Also, how would you like me to document the process/results?

Thanks!

Quote:

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Originally Posted by MountainStone

lemme ask: with my high calcium level, will adding cal hypo cause any problems? It is my understanding cal hypo adds calcium, and my level is currently 600ppm and rising weekly due to desert evaporation and high fill water calcium.

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Ironically, the answer is, "No, it will probably reduce your calcium levels!"

But that's true ONLY if you do it as I describe -- adding it via the skimmer, and gradually raising your pH. If you add it to the pool, it will make a mess. Added through the skimmer, it will STILL make a mess, but on your filter. That's why you'll need to clean more. But, on your filter, the 'mess' should just be an easy-to-wash-off calcium powder.

However, it's precisely this 'mess' that will both capture calcium from your water AND metals like copper and iron. That's why you do NOT want to allow the pH to drop -- and redissolve calcium or iron -- while you're using the cal hypo. Instead, you want to gradually and steadily RAISE the pH to around 8.0, maybe a month after you first start using cal hypo.

Just remember, till it's dissolved, cal hypo reacts badly with almost everything, including other forms of chlorine. Do NOT allow it to contact any other chemical. (Borax is an exception, and is OK. In fact, I may end up having you add cal hypo and IMMEDIATELY follow it with small borax doses.)

Quote:

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Also, how would you like me to document the process/results?!

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Ideally, a daily log, or at least, a log of each day where you test or add + plus photos of the stains, if that's possible. (May not help -- hard to photo the stains through the water, as you know.)

Wondering how the stain removal went . . .

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MountainStone has not been active on the forum since April, so I'm closing this thread.

Moderators and Team Members, please take discussion of this topic to the Team forum.

Thanks, Ben

I have a fiberglass pool, and live in the middle of the woods with a mesh cover - so when I open, my pool is dirty and there are always some leaves that find their way under the cover. First thing I do is vacuum to waste, add lots of bleach and let the filter run 24/7 till the water clears. Once clear there is usually staining (due to keeping the chlorine at shock levels for a few days). I don't bother balancing the water until I finish the stain treatment because after the treatment you have to rebalance anyway. Once the water is algae free and reasonably clear I wait about 2 days till the chlorine comes down to about 2, I put the filter on circulate, I add the ascorbic acid, enough to go around the pool on the sides (about 1 to 2 lbs.) and let it recirculate for about 1/2 hour, and make sure there are no more stains. When the stains are all lifted I add 2 bottles of sequestering agent. I let this recirculate for about an hour. I then put the pump on filter and add 1 puck to my skimmer basket. ( I know this is not recommended, but I do it so that there is some chlorine going in the pool, and I never had any problems with this) Then I keep the filter on 24/7 for a day and start to slowly add chlorine to my pool. The pool will not hold chlorine, so you have to keep adding it until all of the ascorbic acid is gone. Depending on how much you use will depend on how long it takes to hold chlorine. Since I don't have to worry about a liner, I don't worry so much about getting the ph up. I do it slowly, and watch for stains to return. If I am all clear I get the water balanced. Last year I did use the CuLator, and it seemed to work well for me. I am going to use it again this year and will let you know how it does. I may even do some experimenting to see what happens if I get my chlorine high with high ph. All I have learned about getting rid of stains has been by experimenting and seeing what works - it always helps to have everyones feedback, so we can learn from each other.

Marie,
It is great to see you back on the forum! We have missed you and also your great advice for so many people who have stain problems in their pools!

Again, welcome back!

Thanks Watermom!, it's good to be back.