My test says Chlorine is high but pool guy says low

[Truant]

Hello, I'm a new pool owner so I'm still learning the chemistry involved in maintaining a pool. Since I didn't trust myself yet we hired a service to maintain the pool. Just out of curiosity and for my own learning I bought some test strips and I'm concerned about the chlorine levels. Here are some details about the pool:
25k gallons
In ground
Vynyl liner
Hayward pump and DE filter

I used two test strips, one by HTH and the other aquacheck 7.
On the HTH stick:
Free chlorine maxed out 10+ppm
PH 7.5
TA 80
TH 200
CYA 100

On the aquacheck :
Free Chlorine 20
Total chlorine 5
PH 7.5
TA 100
CYA 100

Do these numbers look OK? The pool is clear but I'm worried about too high chlorine. I apologize if I left out any information.
Thank you!

 

[Earl Cox]

Hello welcome to TFP. Test strips are not recommended because they are not accurate. You will need to purchase one of the Recommended Test Kits.

 

[woodyp]

Let's get you to add a signature line to you profile so you don't have to keep listing pool specs. I wouldn't trust either of those stick tests. Do you and your pool a favor and get one of our recommended test kits. You'll never look back. Welcome to the forum.

 

[440dodge440]

Double check your numbers....Total Chlorine= Free Ch+Combined Ch....FC cannot be greater than TC

 

[Richard320]

Hello, I'm a new pool owner so I'm still learning the chemistry involved in maintaining a pool. Since I didn't trust myself yet we hired a service to maintain the pool. Just out of curiosity and for my own learning I bought some test strips and I'm concerned about the chlorine levels. Here are some details about the pool:
25k gallons
In ground
Vynyl liner
Hayward pump and DE filter

I used two test strips, one by HTH and the other aquacheck 7.
On the HTH stick:
Free chlorine maxed out 10+ppm
PH 7.5
TA 80
TH 200
CYA 100

On the aquacheck :
Free Chlorine 20
Total chlorine 5
PH 7.5
TA 100
CYA 100

Do these numbers look OK? The pool is clear but I'm worried about too high chlorine. I apologize if I left out any information.
Thank you!

Welcome!

Something ain't right. Free chlorine can never be higher than total chlorine. Ideally, they would be the same, actually. Recheck those numbers, although as already said, test strips aren't good enough.

It sounds like maybe the pool guy "shocked" the pool. In reality, he just raised the chlorine a bit. Shock level would be more like 40 FC for your 100 CYA. Those high levels of chlorine aren't really all that high. Pool School - Chlorine / CYA Chart

Have you read Pool School - ABCs of Pool Water Chemistry ? That's a good starting point.

 

[Truant]

I apologize for the numbers, unfortunately the legend for the stick test had a max reading for total chlorine that was lower than the free chlorine maximum. But, I also could have misread them. I have a tf100 kit on it's way and will take a sample of water to the pool store tomorrow. I did test the water with an older kit with OTO and phenol red but again, the chlorine maxed out on the scale. I read I could dilute the sample but that might also screw with the numbers from any chemicals/hardness in my water. Thank you for the links and I'll read over everything tonight and hopefully get better information in the morning.

 

[JamesW]

If the pool person is saying that the chlorine is low, it's likely that they are using regular DPD and it's bleaching out.

 

[smackdab]

I've used aqua chem test strips before and they will show a lower TC than FC every time. I don't know why but that isn't possible but that is what they show.

 

[Truant]

I apologize for getting back so late, I finally got my test kit and was able to test the chlorine levels. This is what I got:
Free Chlorine: 26ppm
Combine Chlorine: 1ppm
CYA: 100+
Ph 7.2
TA: 40
Hardness: 100

The CYA is 100+ because the black dot disappeared before the 100 mark on the test tube. I did have a test strip that said it was between 100-150 though.
According to the chart I saw, my FC target should be around 12 with a shock of 39. I haven't had any chlorine or any chemicals added to the pool in two weeks and the sun has been pretty bright here lately. Are these levels way too high? I compared a picture of my pool from last year to now and I noticed that my vinyl pool liner has faded a good amount. I'm worried they ruined with the the high chemicals. Here is a picture:

The liner used to be more vibrant and not have those splotches.
Thank you all!

 

[Crackerjack4u]

Hello Truant, and welcome to TFP,

By your readings I see a couple things that stick out already one is your CC is 1ppm which tell us something could be going on in there, and your CYA level is above the reading of the test tube for the standard CYA test.

So, First things first, lets determine exactly what your CYA level is by asking you to perform a diluted CYA test:
To Do this:
Add pool water to bottom 7ml line of your plastic CYA bottle.
Add tap water to top 14ml line of the plastic bottle.
Shake to combine.
Pour out half of the mixture so it is at the bottom 7ml line.
Add the Cyanuric Acid reagent up to the 14ml (top) line.
Shake to combine.
Pour the contents from the plastic bottle into the appropriate tube until the Black Dot disappears

(NOTE: Be sure to perform the test with good indoor lighting or with the sun to your back when performing it outside. You can pour the liquid back and forth from the test tube to the plastic bottle several times to ensure you get the same reading each time).

Multiple the results by 2. (This is your CYA level).

Once you complete that please post the level on here and we can go from there. Have a nice night.

 

[Truant]

Thanks, I'll dilute a sample tomorrow and let you know what the CYA is. For the CC, after I cleared the solution and added R0003, the solution didn't really change color (it was very faint). Then I added two drops of 871 and it was clear again. (This was a 10ml sample) Is having a low CC bad? My pool is clear and doesn't smell but I do have some metal staining on the steps that needs to be taken care of. Thank you again!

 

[MarianParoo]

Welcome. You want your CC to be as close to zero as possible.
You can put a vitamin C tablet (cheapo tabs are fine) on the steps and let us know if you see any reaction.

 

[Truant]

Ah, ok, good. My reading might have been even less than the 1ppm that I wrote then. Since I had only 10ml to I could only gauge in .5 ppm increments. I bought some vitamin C at CVS (hopefully there is a cheaper way?) and did test a small test and it cleared it up like magic! Could metal staining cause those splotches on the vinyl liner too?

 

[Crackerjack4u]

You're welcome.

When CC is present it is either from algae, or from other contaminates (If neither of them are present your CC level will be zero we use a baseline of 0.5ppm, or less. But yes, with you being new to testing it very well could be less than what you actually recorded. It just takes a bit to figure those tests out sometimes, but hang in there they'll get much easier to figure out as time goes on. ).

The CC level is kind of a tattletale sign that often, especially in a clear pool with no visible algae present, helps us see a potential problem, and be able to quickly clear it up before it becomes a full blown issue.

With your CC only being 1ppm, whatever the cause is, if your number Is correct, it's nothing serious. So even if it's algae, hopefully it can be easily eliminated in a short period of time with your chlorine at shock levels per the Chlorine/CYA chart:
http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

But 1st we need to know what your actual CYA level is in order to properly advise. So once you do the diluted test
then we can better determine where to go from there.

I hope this helps, and Have a nice night.

 

[Casey]

Welcome to TFP.

Before you dive into a solution for your metal staining, you should get your test results in line. The CYA is way to high and a partial drain refill will bring it down. Once you get an understanding on where everything needs to be, then you can address the metals.

The ABC's of Pool Water Chemistry is a great place to start. I have a direct link to it right in my signature.

 

[MarianParoo]

When you do your diluted CYA test tomorrow as planned (assuming you are correctly waiting for full sun), here's a tip: When you do the diluted CYA test, "pour out" the 7ml somewhere safe in case you pour out too much. That way you can adjust back up to 7ml. I have a 10ml syringe I got from the drug store that also has markings for 3.5 ml. Medical accuracy...

Interesting news on the vitamin C. That's actually good info we can use later.

 

[Truant]

I diluted a sample of water and tested the CYA again this morning and it read 140ppm (70*2). All the literature I've read seems to indicate this is pretty high, but my main concern is any damage I may be doing to the pool and the pumps. This is about the time when we close the pool so I imagine this will need to get fixed before we do that.

 

[DaninFLA]

no issues with damage to your pool and pumps. if the stains are removed with vitamin C that's a good thing and means it can be addressed. but right now the biggest concern is getting your CYA under control. with a vinyl liner, you should drain your pool until you have about 1 foot of water in the shallow end. don't do any lower than that or you could risk your liner shifting, etc. hopefully doing this would be close to a 50% drain and cut your CYA in half. you can then retest your CYA and go from there. since you are going to close, I would say to do the one drain and refill and then follow the TFP pool shut down instructions. When you open your pool next year, you can do an additional drain and refill to further correct the CYA if needed.

and more thing...fire your pool service immediately, you don't need them

 

[Crackerjack4u]

That's about what we were expecting to see. I agree with Dan that In order to properly fix the issue you will have to do a partial drain of probably at least 50% then refill.

(If you are getting ready to close, and do in fact drain down below the skimmer for the Winter then the refill next Spring will help bring it down, but the main concern there is it will be difficult to try to keep it adequately chlorinated through the Winter to prevent opening to a green pool next Spring. The high CYA isn't actually damaging your pool/equipment but it's going to cause you a lot of problems trying to properly sanitize your pool because it's so high.

The problem with a CYA that high is that it is nearly impossible to maintain your chlorine at the appropriate levels to prevent algae from growing in there. Then once you do get algae (as unfortunately someone with that high of a CYA most always has occur), then attempting to SLAM at even higher chlorine SHOCK levels for that CYA, and maintain those during SLAM, as is required to kill out the algae, is even more difficult, if not near to impossible to achieve.

In order to try to prevent algae from growing you have to MAINTAIN your chlorine level at approx. 9-16ppm at all times. If you do get algae in order to SLAM your pool to kill it out, the Shock level you'd have to maintain would be like 55-56ppm , or you'd be continuing to have a green pool and be constantly battling algae. So, as you can see it is so much easier/obtainable to fix the problem now, and maintain your pool at the lower chlorine levels needed for a lower CYA level to prevent algae outbreaks.

NOTE:Also, It is recommended that you don't close your pool until the temperature is 60F, and then reopen next Spring before the temperature gets above 60F to help ensure you open to a clear, not a green pool. I hope this helps. Have a wonderful day

 

[Truant]

Thanks for help again everyone! It's a relief to know that I'm not damaging the equipment or pool. The pool company is definitely fired, I just can't believe they knowingly let it get out of control without notifying me (we called them many times over the summer).
I'll get someone out to drain and fill the pool. We will probably postpone the pool closing. It has been getting colder up here (50's at night) so we're probably close to that 60 degree mark. Thank you again everyone for taking time to help!

Sorry, but one last question. The fading we noticed in the liner, could that be from the chlorine/cya levels or could it be something else, like staining that I can clean?