New to testing and conflicting results issue

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duraleigh said:
MITbeta, What does that mean? Is there a copper test in this thread?
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The pool store test printout in the first post has copper at .3. That's at the threshold where it can start to cause staining and is not surprising with a pool service handling the chemicals for 6 months +. They sure love their algecides and 5-in1 tablets.
 
I was suspecting a recently treated pool with chlorine gas. Am I correct? It will lower itself before next visit.
I also saw the copper result.....about the ONLY test we let pool stores do as they muck up most others. I suspect the store couldn't get a higher accurate FC reading so just said "15", enough to scare newbies for sure.

Maddie :flower:
 
OWSwimmer said:
Hello, I’m starting to learn how to monitor and treat my 1 year old pool and could use some help transitioning from the pool maintenance company. I’m not letting them go until I feel comfortable understanding and doing the testing myself.

I could use some help since I’m finding wildly different testing results from my maintenance company, Leslie’s and my own TF-Pro Salt test kit.

I’m pretty comfortable testing for pH, Chlorine, TA and CH but I’m a little apprehensive with the CYA test since it’s so subjective. I got 50-60 CYA.

I’ll post pics of same sample results from my testing and Leslie’s. My maintenance company doesn’t provide results but claims all is well.

It’s cold here, my salt generator isn’t running and I haven’t tested the salt level but it’s been around 2250.

So what do I have here and what should I be doing?

Thanks.
View attachment 472635View attachment 472635View attachment 472636
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To answer a specific question, the pool stores very very very frequently provide inaccurate test results. It’s not on purpose, but a reality. Once you’re settled in, try taking the same water sample to three different stores and see what you get and do a search for others here that have done the same to get an idea of how bad it could be.

Your TF test kit is good. If the only trouble you are having is the CYA, you’re doing fine. Even if the CYA is off by 10ppm, it’s no big deal. The tests all have tolerances (including the pool stores) and I think the tolerance for the CYA test is around +/- 10ppm. Can’t remember exactly.
 
Follow up and latest testing results. When I test the FC I get 36 ppm when it looks like only 4-11 ppm are called for.
My company says the FC will be off the chart high because they use a tank filled with chlorine gas to add chlorine when needed.
Why is the FC this high when using chlorine gas?
Here’s a pic of my testing done just before their service yesterday. They didn’t add anything and only tested. I do have a SWG but it’s not running now due to the temp.
Are these numbers ok?
thanks!
30D16DA8-B00A-4EFB-9FC2-8BBC6D6AABB0.jpeg
 
OWSwimmer said:
Are these numbers ok?
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If they are accurate - no. Some work needs to be done such as:
1. Ensure the FC goes no higher. It needs sunlight and to be allowed to fall at least below SLAM level (31) based on that CYA of 80. See FC/CYA Levels. Until then, no one should be in the water.
2. The TA is too low. Add about 20-40 ppm worth of baking soda to take the TA up to about 50-60.
3. Watch the CYA. It's a tricky test we know, but no higher than 80.
 
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That's how chlorination with gas works. You add a ton of it so it lasts until they come next time. It also crashes pH and TA, so baking soda is usually required when using chlorine gas.

To maintain a lower, more constant FC level following the FC/CYA Levels, chlorine needs to be added in smaller quantities on a regular basis. Either with chlorinating liquid (sodium hypochlorite) or, much more convenient, using a salt water chlorine generator (SWG), which you are in the lucky situation to have. While the SWG is not working due to low temperature, the best way is to manually add liquid chlorine by yourself. How often you have to add, you need to determine by testing and monitoring your chlorine losses.
 
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mgtfp said:
That's how chlorination with gas works. You add a ton of it so it lasts until they come next time. It also crashes pH and TA, so baking soda is usually required when using chlorine gas.

To maintain a lower, more constant FC level following the FC/CYA Levels, chlorine needs to be added in smaller quantities on a regular basis. Either with chlorinating liquid (sodium hypochlorite) or, much more convenient, using a salt water chlorine generator (SWG), which you are in the lucky situation to have. While the SWG is not working due to low temperature, the best way is to manually add liquid chlorine by yourself. How often you have to add, you need to determine by testing and monitoring your chlorine losses.
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My chlorine (total) seems really high. But I need to add more chlorine?
 
OWSwimmer said:
My chlorine (total) seems really high. But I need to add more chlorine?
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Let's take a quick step back.

1) When it is warmer, your SWCG should be adding FC everyday to keep your FC level steady.
2) Foundational to TFP is that we test daily (with a good Test Kits Compared) and add liquid chlorine, or run a SWCG to maintain a consistent FC aligned to the level of CYA you have in the water LINK-->FC/CYA Levels.
3) In your situation, pool company using chlorine gas...their approach is to raise your FC high enough so that it will not get too low when they come back, and you won't have algae. The problem is they are not testing, they have no idea how much FC the pool will use during the week, and added so much chlorine that your FC level is not safe to swim until it comes down to below 40% of your CYA. We call that level SLAM level and is used in this process LINK-->SLAM Process
4) To answer your question, yes, you need to add chlorine WHEN your FC gets to the lower end of the recommended range for your CYA (your log says 80, so your range is 6-11) as recommended in the FC/CYA article link.

What the pool company is doing is feeding your pool once a week (or whatever frequency) vs. feeding your pool once a day. Said another way, if you need 2000 calories to survive daily, you would eat 2000 calories (TFP). They are just feeding you calories (more than the 14,000 you need for the week) and hoping that is enough. They put A LOT in so it will last until they come back again.
 
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mgtfp said:
Are they adding liquid chlorine to the pool or injecting chlorine gas?

(Edit: I should clarify that with "liquid chlorine" I am not referring to liquified chlorine gas under pressure in the chemical sense, but to chlorinating liquid aka sodium hypochlorite or bleach in the pool maintenance sense.)

Liquid chlorine is pH and TA neutral (over the complete chlorination cycle).

But dissolution of chlorine gas in water is an acidic process. In terms of pH/TA, a gas chlorinated pool has to be treated similar to a tabs chlorinated pool, it'll need baking soda to compensate the TA decrease.
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They add chlorine gas injecting it from a tank device placed in the bottom of the deep end.
 
PoolStored said:
Let's take a quick step back.

1) When it is warmer, your SWCG should be adding FC everyday to keep your FC level steady.
2) Foundational to TFP is that we test daily (with a good Test Kits Compared) and add liquid chlorine, or run a SWCG to maintain a consistent FC aligned to the level of CYA you have in the water LINK-->FC/CYA Levels.
3) In your situation, pool company using chlorine gas...their approach is to raise your FC high enough so that it will not get too low when they come back, and you won't have algae. The problem is they are not testing, they have no idea how much FC the pool will use during the week, and added so much chlorine that your FC level is not safe to swim until it comes down to below 40% of your CYA. We call that level SLAM level and is used in this process LINK-->SLAM Process
4) To answer your question, yes, you need to add chlorine WHEN your FC gets to the lower end of the recommended range for your CYA (your log says 80, so your range is 6-11) as recommended in the FC/CYA article link.

What the pool company is doing is feeding your pool once a week (or whatever frequency) vs. feeding your pool once a day. Said another way, if you need 2000 calories to survive daily, you would eat 2000 calories (TFP). They are just feeding you calories (more than the 14,000 you need for the week) and hoping that is enough. They put A LOT in so it will last until they come back again.
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What’s wrong with my math?
When I do 40% of my CYA (of 80) I get 32. Not sure how to arrive at 6-11. I think this means I need FC to be below 32 per my current CYA and ideally my FC should be 6-11. Is this correct?
 
OWSwimmer said:
What’s wrong with my math?
When I do 40% of my CYA (of 80) I get 32. Not sure how to arrive at 6-11. I think this means I need FC to be below 32 per my current CYA and ideally my FC should be 6-11. Is this correct?
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Slam level is 40% which is the max. Ideally you be running at or above 7.5% for everyday operation.
 
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Im going to start treating my pool myself when my pool company contract expires and when I get a better handle on pool chemistry. For now I have a company treating my pool with liquified chlorine gas. Im having trouble understanding my TF Pro Salt test results compared to the test results of my pool company. Im routinely getting a FC result of 30- 40 and the chlorine comparator is off the chart dark orange. The pool company tells me this 30-40 FC is the same as a “3 or a 4” if I were using granular or tablets. Ive been unable to find any kind of supporting data on this and the company can’t provide any claiming “its a trade secret” of the product from “California Chemicals.”

Also, my TA routinely tests at 40 but the company keeps getting “90” claiming I’ll get “false low readings across the board” with my test kit since liquified chlorine gas is being used.

This company has been in business for 40 years, does 500 calls a day and has many satisfied customers. I need a better understanding of what it is that Im seeing. Is my test kit useless as long as liquified chlorine gas is being used?

Any input from the folks here at TFP?
Other results:
CYA 60
Temp 60
ph 7.7
CH 175
Salt 1800
CSI -1.05
TY!
 
It’s just chlorine gas and it’s not liquified. Chlorine gas injection has been around a long time. It’s not a great method for sanitizing a pool as it is very dangerous and requires a skilled operator and specialized equipment. It’s is quite common for gas shooters to over chlorinate a pool as that is how they are able to keep it down to a once per week visit. They essentially super-chlorinate the water and then tell you not to swim for a day. Depending on your CYA level that may (or may not) be ok. Injecting chlorine gas into the water is a highly acidic process leading to a steep drop in TA and pH. Very often they have to add soda ash or baking soda either during or after the process to help the pool recover.

Your reading are not at all unusual and the only “interference” you are getting with your test kit is that the chlorine levels are too high making many of the tests difficult to perform. The TA test can be affected by the highs chlorine levels unless you add enough of the R-0007 to compensate for the high FC. I am not surprised that you’re seeing a TA of 40ppm. My guess is the pool service guy isn’t being very careful.

You are better off getting away from the gas shooter process. It’s causing the FC to spike and then probably falling dangerously low before the next visit. It’s a terrible way to treat a pool.
 
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