Using Ascorbic Acid to eliminate chloramines

Jump to latest Follow Reply
lesandov

lesandov

0
Jul 7, 2015
20
Tepic/Nayarit/Mexico
Hello Everyone,

I was doing some research on chloramines and I found this article about using ascorbic acid to eliminate chlorine and chloramines from tap water. http://www.sfwater.org/Modules/ShowDocument.aspx?documentID=6920. It seems that Chloramines are a fairly common method to sanitize water in city water and sewing systems across the US.

I was wondering if it was possible to remove choramines from my pool water, so I took a water sample in a 20 lt. bucket, test it for FC and CC (FC=17 and CC=2), added two grams of ascorbic acid and let it rest for about 12 hours. To my surprise, FC and CC levels showed zero!

I've been struggling with high chloramines levels for several weeks, so I wonder if using some reasonable amount of ascorbic acid would help me to lower my CC level to .5

The article from the San Francisco Water and Sewer System, states that for a medium size bathtub, using 1 gr. will suffice to "clean" chlorine and chloramines out. If I assume that a medium size bathtub can hold about a 100 lts. then I probably could use around 650 gr. for my 65,000 lts. pool. Probably a little bit less to just lower the CC level without exhausting FC.

I know that Ascorbic Acid can be used to eliminate metal stains, so I think it is safe to use on my water and thus worth to try on the CC issue.

Any comments on this?
 
Sunlight and FC will lower CC. Why are you focused on lowering CC? They will go away on their own once there is no organic material being oxidized in the pool.
 
Yes, it is an Indoor Pool.

For the last four to six weeks I've been registering high CC levels, ranging from 1.5 to 2.0 ppm. This might be due to a high bather load, which is around 12 to 15 people swimming and exercising every hour (mostly elderly and toddlers), from 7 thru 11 hours and from 16 thru 20 hours, monday thru friday. I am worried that having such significant CC levels becomes a health issue amongst my patrons.

As you may see, weekends are the only chance I have to perform SLAM, but it just seems to be not enough time to pass the OCLT test and take CC level down to .5

So that's why I am looking forward to find alternatives to keep CC on the line. UV, Ozone and Activated Carbon systems are most probably beyond my current budget. So here we are....

I keep my FC levels ranging from 6.5 to 10 ppm daily, with a cya around 20-30 and keep adding MPS @2 kg per week.
 
If you have access to potassium monopersulfate (MPS, also know as non-chlorine shock), you can try using that as a secondary oxidizer to eliminate CCs. The only problem is, they will interfere with the Taylor reagents and show up as CCs on the test. There is a special reagent you can purchase to eliminate the interference caused by MPS so you can accurately measure your CC level. MPS is useful in indoor pool water management for high CCs. It sounds like you have very significant bather load with both elderly and young patrons. They are both well know for "relieving themselves" in pools rather than bathrooms.
 
I keep my FC levels ranging from 6.5 to 10 ppm daily, with a cya around 20-30 and keep adding MPS @2 kg per week.
Click to expand...

I think your higher cc levels are reading as such BECAUSE you're using MPS, which as Matt pointed out, skews the test! So try the nose test...do you SMELL chloramines? If you can't really smell a heavy chlorine smell then your real chloramines are not likely as high as you're reading ;)

Re: Ascorbic acid...if you used it, it would then fight your chlorine and I'm not sure you'd successfully get back up to FC level required for weekday operation. Not likely practical.
 

Enjoying this content?

Support TFP with a donation.

Give Support
JoyfulNoise said:
If you have access to potassium monopersulfate (MPS, also know as non-chlorine shock), you can try using that as a secondary oxidizer to eliminate CCs. .
Click to expand...

Yes I use MPS every week. I toss around 2 kg. according to manufacturer recommendations. I believe it helps to prevent chloramine accumulation, but it won't really help to eliminate them, at least not in the short term.
 
pooldv said:
Are you using CYA in the pool? That will allow you to run higher FC to help during the off hours. [FC/CYA][/FC/CYA]
Click to expand...

There is some CYA in the water as I use dichlor eventually, just to keep the level around 20-30. I follow Pool Calculator suggestions to set the amount of dichlor. With that in mind I try to keep the FC level above 4 ppm. Since the CC level, most of the time I add enough bleach to take FC to the shock level, 10 ppm according to FC/CYA chart.
 
Swampwoman said:
I think your higher cc levels are reading as such BECAUSE you're using MPS, which as Matt pointed out, skews the test! So try the nose test...do you SMELL chloramines? If you can't really smell a heavy chlorine smell then your real chloramines are not likely as high as you're reading ;)
Click to expand...

That makes sense, but with such a high bather load, shouldn't MPS get depleted in just a day or two? I usually drop in the MPS on sunday morning and won't take a FAS-DPD test reading until tuesday morning. I keep sanitizing with bleach normally until next sunday. Do you think CC test outcome, performed on let's say thursday or friday, can still be affected by last sunday's dosage? Probably the best way to find out is to get the reagent that eliminates the interference.

I don't really perceive the heavy smell to chlorine, which makes me feel more comfortable; but, my main instructor, which happens to be my wife, often claims suffering eye irritation and skin rush, she spends about six hours in the water and that might be a factor. However, I haven't receive complaints from other patrons.

Swampwoman said:
Re: Ascorbic acid...if you used it, it would then fight your chlorine and I'm not sure you'd successfully get back up to FC level required for weekday operation. Not likely practical.
Click to expand...

I'll keep Ascorbic Acid away from my pool for the time being.

- - - Updated - - -

I want to thank you all for the great responses. There has been a lot of great ideas around in this thread!
 
Using only chlorine in a heavily used indoor pool really is not practical. You need a supplemental system such as UV or ozone. However, to be done correctly, you need someone who really knows what they're doing.
 
As a new visitor here, just trying to learn whatever I can, I thought I'd ask... Regarding this situation, I thought the CYA was basically needed as a stabilizer to prevent the FC from being removed by the sun... With an indoor pool, if you dont have the sun to deal with, why wouldn't you want the stabilizer levels to be as low as possible, to keep the FC more effective, and just chlorinate with liquid all the time? Does the CYA perform another function, or would the FC just get used up ridiculously fast with near zero levels of CYA?
Just curious.. I'm not likely to ever manage an indoor pool, but just trying to understand the chemistry as best as possible!!

Thanks from a newbie that has a CLEAR BLUE pool instead of the green mess I had last week thanks to finding this forum!! (And the GOOD test kit is in the mail!!)

-Steve
 
172pilot,

CYA serves two purposes. The first you mentioned is correct, it stabilizes FC against UV photolysis.

The second function is this - CYA is a chlorine buffer. When present in water even at low concentrations, over 90% of the chlorine in water is held in reserve thus lowering the active chlorine (hypochlorous acid and hypochlorite) concentrations to comfortable levels. Even in an indoor pool it is recommended to have 20-30ppm CYA.

If one were to use very low or no CYA in an indoor, then the chlorine level added would be too harsh and would bleach hair, bathing suits, etc. One would have to use very low FC levels to make the water comfortable and that would be impossible to control. As well, when no CYA is present, the proportion of nitrogen trichloride to monochloramine is higher (they are both CCs) and nitrogen trichloride is a very irritating CC to have in an indoor space.

So even though UV is not present in an indoor pool, CYA is absolutely essential to an indoor pool.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply