Post Ascorbic Acid Treatment - Strange Test Results

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T

TexasToast

Member
Jul 13, 2021
12
The Woodlands, TX
Pool Size
14000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello! I'm new to the group, so please correct & guide me if I forget to include any pertinent details. Here goes:
We have an IG plaster pool, approximately 14K gallons - it came with the house, so there has been a lot of trial & error on our part to figure out the ins & outs of caring for it properly. For example, we had been using trichlor pucks for years before learning about CYA *facepalm*. Another example is that my husband was under the impression that all we needed to do to maintain the water was to add chlorine & shock it every week *facepalm #2*. Long story short, less busy me has taken over the pool care from the very busy him.

Which brings us to my current issue at hand (and longest backstory ever)...
We've got stains, some old, some new, did the Vitamin C test, which worked in certain areas, so proceeded with an ascorbic acid treatment on 7/10. Let me preface this info with some numbers - I tested myself on 7/7 & had Leslie's test to verify my results as well as to check for metals.

Mine (did each test twice, except FC & CC)
FC - .2
CC - .2
pH - 7.8; 8.0
TA - 150; 140 (adjusted to 120 with CYAf of .35)
CYA - 60; 57 (this was 300+ last summer!)
CH - 420; 475

Leslie's
FC - .21
CC - .21
pH - 8.3
TA - 107 (adjusted for CYA)
CYA - 68
CH - 389
Iron - .1
Copper - .1
Phosphates - 534
TDS - 750

So, the pH & CH were in major disagreement, & TA only slightly. Chalked it up to pool store discrepancy, but very relieved to see the decrease in my CYA (don't have to drain the pool now, yay!) then proceeded to lower my pH to 7.2 over the course of the next couple of days using muriatic acid.
7/9 - New cartridge filters arrive in the mail. Internal debate to wait til this is all done to swap them out ensued. Decided to change them now because current filters are in pretty bad shape & not the right size! (Hubby took old one in to the store last year to ask for something to match, not realizing previous owners had the 880's instead of the correct 1380's *facepalm #3*.)
7/10 - Added 24oz Polyquat 60; later added 2lbs ascorbic acid; later added 2qts HTH Metal & Stain Defense.
Filter has been running for a couple of days, noticeable improvement in many of the stains, but not fully cleared, brushing everyday, waterfall runs for about eight hours a day.
7/13 - Water is looking a little cloudy, so I test & take a sample to Leslie's for comparison.
Mine
FC - .2 (had to add nine or ten additional dippers of R-0870 for sample to turn pink)
CC - .2
pH - 7.5
TA - 80
CYA - <30
CH - 500; 475 (tested 2x)

Leslie's
FC - .36
CC - .36
pH - 7.7
TA - 79
CYA - 24
CH - 357
Iron - .2
Copper - 0
Phosphates - 1411
TDS - 800

Also, water temp is 83, and we've gotten about 1.5" of rain in the last week (7/6-7/12). My questions are:
1. My CYA levels have decreased dramatically. What could have caused this? It can't possibly be just from the rain.
2. Going from my numbers rather than the pool store, is my high CH cause for concern? We do have calcium scale from the previous manner of care, which will be my next project, but there was a substantial increase over the six day span of time, from around 420 to around 500, how did this happen?
3. How should I proceed to re-balance the water? Should I bump up the TA & CYA a bit before beginning to the process of adding liquid chlorine?
4. The dramatic increase in phosphates - is this due to the sequestrant? I do have slight algal growth at this point, but nothing more significant than six days ago.
5. Cloudy water - likely caused by the ascorbic acid (did this on 7/10 & cloudiness began to creep in 7/12), or the high CH?
It's a lot of information to process, I know. Please let me know your thoughts & how best to proceed from here. Thank you!
 
1. My CYA levels have decreased dramatically. What could have caused this? It can't possibly be just from the rain.
2. Going from my numbers rather than the pool store, is my high CH cause for concern? We do have calcium scale from the previous manner of care, which will be my next project, but there was a substantial increase over the six day span of time, from around 420 to around 500, how did this happen?
3. How should I proceed to re-balance the water? Should I bump up the TA & CYA a bit before beginning to the process of adding liquid chlorine?
4. The dramatic increase in phosphates - is this due to the sequestrant? I do have slight algal growth at this point, but nothing more significant than six days ago.
5. Cloudy water - likely caused by the ascorbic acid (did this on 7/10 & cloudiness began to creep in 7/12), or the high CH?
It's a lot of information to process, I know. Please let me know your thoughts & how best to proceed from here. Thank you!

LOL your facepalms :laughblue: GO GET SOME CHLORINE IN THE POOL!!

1) Have you drained water when your typical Houston rain has filled the pool?? If that rain water was mixing a while with the pool water, then you remove water you'll lose CYA. CYA only goes away to any extent by draining water or splash out. It does degrade but too slow to count on.

2) You got 475 CH twice. I'd accept that as your FC level. If you're feeling like scale is developing you can drop your pH down and keep it around 7.2 and that will help balance that out. Do you use PoolMath- it provides a CSI number which can be helpful to plaster pool owners who have to manage CH vs scale.
www.troublefreepool.com

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.
www.troublefreepool.com www.troublefreepool.com
www.troublefreepool.com

Calcium Scaling

Calcium scale on your pool is something we all want to avoid. With some elbow grease and a pumice stone for pools we can help you remove this eyesore.
www.troublefreepool.com www.troublefreepool.com

3) Your TA is fine at 80ppm. Yet you may want to tweak it to help your pH stay low-ish longer. If you plan on using Liquid Chlorine from now on, being in sunny Texas, go ahead and take the CYA up to 40 or 50ppm max. Remember to plot this out with PoolMath first to see how everything effects the CSI.
www.troublefreepool.com

Lower Total Alkalinity

A lower Total Alkalinity level can help a pool owner stabalize their pH increase. We'll explain how to lower TA with a little help from muriatic acid.
www.troublefreepool.com www.troublefreepool.com

4) Ignore phosphates as long as you're going to keep your pool's FC level at the correct level to the CYA. FC/CYA Levels
If *ever* you felt you had to deal with phosphates, never buy the fercoctah crummy stuff Leslie's tries to push on you. There are better products.

5) Cloudy water in your case is slightly confusing- is it algae (most likely) or a result of the Ascorbic Acid you used. That acid eats thru chlorine and makes you vulnerable (hence you added the Polyquat60 to help avoid problem). Calcium usually only makes cloudy water immediately when you add it and cloud for a day or so, or when you have horribly high levels & its laying around the floor of the pool and you're brushing it up.

It sounds like you need a SLAM process and liquid chlorine only.... SLAM Process Keep an eye on the filters and wash 'em out when the filter pressure rises 20-25%, no sooner.

Please do NOT go to Leslie's for testing. The kit you have is an excellent kit and I trust those results. Going to Leslie's for a double check just confuses folks.

On my lap top I can use the old web version of PoolMath, and enter in "current" numbers in one column, then use the "target" column to tweak my chem level suggestions and see how potential changes can change your CSI. Try to stay slightly negative or as close to zero, but don't beat yourself crazy chasing numbers. Also, remember to enter your pool size up top, then go all the way down and enter pool type, how you chlorinate, and what you wan to base your levels on (correct answer-"Troublefreepools")

Did you know which metals you were dealing with when you did that acid treatment?? Did you by chance use copper containing pucks like those horrible Clorox Xtrablue ones?

Maddie :flower:
 
Thank you for the response Maddie! Copied your answers below so I don't forget anything...

1) Have you drained water when your typical Houston rain has filled the pool?? If that rain water was mixing a while with the pool water, then you remove water you'll lose CYA. CYA only goes away to any extent by draining water or splash out. It does degrade but too slow to count on.
--I haven't drained any water, the CYA went from ~60 to ~30 in a span of six days, with 1.5" of rain - seems like a big decrease for that amount of rain water, don't you think? Even if we got 2" of rain, that's around 635 gallons of rain water, so not nearly enough to cut the concentration in half. I'm perplexed by this.

2) You got 475 CH twice. I'd accept that as your FC level. If you're feeling like scale is developing you can drop your pH down and keep it around 7.2 and that will help balance that out. Do you use PoolMath- it provides a CSI number which can be helpful to plaster pool owners who have to manage CH vs scale.
--I agree with the 475 CH, and downloaded PoolMath yesterday, but realized I'd have to give permission to access my microphone & camera, and I don't like using apps that require that. I'll use the web version for sure!

3) Your TA is fine at 80ppm. Yet you may want to tweak it to help your pH stay low-ish longer. If you plan on using Liquid Chlorine from now on, being in sunny Texas, go ahead and take the CYA up to 40 or 50ppm max. Remember to plot this out with PoolMath first to see how everything effects the CSI.
--Order of additions considering I'm in the re-balance phase following ascorbic acid treatment? Chlorine first to raise FC to around 4 or 5, or should I increase TA and/or CYA first?

4) Ignore phosphates as long as you're going to keep your pool's FC level at the correct level to the CYA. FC/CYA Chart
If *ever* you felt you had to deal with phosphates, never buy the fercoctah crummy stuff Leslie's tries to push on you. There are better products.
--No problem here, I've done enough research thus far to know to stay away from all that! ;)

5) Cloudy water in your case is slightly confusing- is it algae (most likely) or a result of the Ascorbic Acid you used. That acid eats thru chlorine and makes you vulnerable (hence you added the Polyquat60 to help avoid problem). Calcium usually only makes cloudy water immediately when you add it and cloud for a day or so, or when you have horribly high levels & its laying around the floor of the pool and you're brushing it up.
--I'm thinking it's from the algae too. Gonna start the process of adding the liquid chlorine tonight & hopefully this will resolve itself.

I can't SLAM for two weeks, the recommended waiting period after AA treatment to keep metals from dropping out of solution. I know we had iron because the vitamin C test confirmed this; unsure of the presence of copper or magnesium - I did put some dry acid in a sock to test some darker stains on the steps, but didn't notice an obvious lightening of the stain. Might end up getting some sort of stain ID kit to determine the nature of what remains. I can't really tell right now because of the cloudiness. Hoping when this dissipates, a miracle will have occurred and my plaster will be shiny & clean. 🤞
I had Leslie's do a retest because I wanted to see if they would confirm the presence of metals, since I can't test for that directly. I also wanted a confirmation of my CYA, since it was over 300 toward the end of last year, I was in disbelief when I got 60 :oops:, then confused when I got <30 six days later 🤨.
We did use the Clorox XtraBlue for many years, and I read that those can add copper to the water, but its been awhile since we last used those.
 
I'm experiencing somewhat of a challenge here, and was hoping one of you experts can help me out. I did an ascorbic acid treatment a couple of weeks ago, and have been in the process of chlorinating to neutralize the AA. My problem is this - I added 4lbs of granular CYA on July 17 (half in a sock in front of a return & the other half in a sock in my skimmer). It was completely dissolved in a couple of hours, and nine days later my test is showing close to zero ppm. I'm not sure what to do next, I need to SLAM but I don't know how much chlorine to add.
Test results on 7/17:
FC - .2
CC - .2
pH - 7.4
TA - 80
CH - 475
CYA - 5
Temp - 86

Testing today (07/26):
FC - .2
CC - .2
pH - 8.0
TA - 100
CH - 450
CYA - 0
Temp - 88

I've only added the four pounds of stabilizer, three doses of 26-30oz of liquid chlorine (12.5%), and today added 39 oz of muriatic (31.45%) to bring down the pH & TA in preparation to SLAM. Should I add more CYA or wait & test again in a week or so? The amount I've already added should be showing up on my test, right? And we haven't had any rain in over a week, so that's not it. I'm perplexed, please help! Thanks!
 
How did you add the CYA ? 4 lbs should be about 30 ppm. If you added it to the skimmer like the label says, it could be trapped in your filter and take a week to dissolve and show on the testing.
 
The CYA test is not clouded at all?

You do realize you need to add liquid chlorine every day, right?
 
It didn't look cloudy at all today. I tested on Friday (07/23) and it was a little cloudy, so I took a sample to the pool store for a more accurate number & they told me it was at 5.
I am currently hanging my head in shame - I knew I needed to stay on top of it - testing & adding daily, but life has been particularly hectic as of late.
 

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mknauss said:
You are just confusing your self. Use your own kit.
Click to expand...
How am I confusing myself? I used my own kit, the least it can show is 30ppm. After adding the four pounds my results were lower than they were before the addition. If anything I'm confused as to how this could possibly be. To backtrack, my CYA has been decreasing by large increments in the past month. On 07/07 it was 68; on 07/13 is was 24; on 07/17 added four pounds; on 07/23 it's at 5.
I do want to SLAM, but had no idea how much chlorine to add because my CYA is out of whack.
 
TexasToast said:
How am I confusing myself?
Click to expand...
Going to the pool store. Their testing is no better than yours, and, quite frankly, inaccurate. They cannot measure a CYA of 5. It is computer number.

For your CYA to decrease in large amounts, you are exchanging water to fresh or have a bacterial issue in your pool water.
Have you checked for ammonia?
 
mknauss said:
As it is likely you will need to follow the SLAM Process, I would sug
mknauss said:
Going to the pool store. Their testing is no better than yours, and, quite frankly, inaccurate. They cannot measure a CYA of 5. It is computer number.

For your CYA to decrease in large amounts, you are exchanging water to fresh or have a bacterial issue in your pool water.
Have you checked for ammonia?
Click to expand...
Click to expand...
I see what you're saying, I did not know that. The only new water added was 1.5" of rain back between July 7 - July 13. I have not checked for ammonia, in fact, you are the first person to suggest that something other than rain or splash out could result in a lowered CYA. How can I check for ammmonia?
 
Last edited by a moderator:
mknauss said:

Ammonia - Further Reading

www.troublefreepool.com www.troublefreepool.com
Click to expand...
Just read through all of that. So I'm going to add 140 oz of chlorine to get me to a FC of 10ppm, then test again in 30 minutes. If it's down to 2ppm at that time, then I have an ammonia issue (even though my pH has been running higher & my CC has been <.5?). On the flipside, if the FC doesn't decrease by ~80%, then this will be the start of my SLAM process, and I'll do an OCLT tonight. Sound like a plan, or am I forgetting anything?
 
You can get an ammonia test or just keep doing the chlorine cycles. Either way you will use the same amount of chlorine.

Once FC will hold, then add CYA.
 
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