Leslie’s test vs home test, what should I trust?

[r2sie2]

I really struggle with my CYA tests do I decided to go to Leslie’s to get a comparison. They came back with u the same as what I show except for a few things. For one they show my FC level at 6 but I get a 4.5. They show my salt at 2339 but I have about 3000 both in my Hayward app and when I test so I’m more inclined to believe their test is wrong. They also show my phosphates way high and recommended a treatment, but I feel like I generally remember seeing on here that it’s not recommended to treat phosphates. Any recommendations?






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Home pool
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Build Type: Plaster
Volume: 11000 gallons
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Latest Test Result Summary:
FC: 4.5 (52 minutes ago)
CC: 0.0 (52 minutes ago)
pH: 7.8 (52 minutes ago)
TA: 80 (52 minutes ago)
CH: 400 (52 minutes ago)
CYA: 70 (52 minutes ago)
SALT: 3000 (52 minutes ago)
TEMPERATURE: 90° (52 minutes ago)
CSI: 0.14 (52 minutes ago)
==========================================
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Test Results 07-19-2022 @ 09:16 AM
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Free Chlorine: 4.5
Combined Chlorine: 0.0
pH: 7.8
Total Alkalinity: 80
Calcium Hardness: 400
CYA: 70
Salt: 3000
Temperature: 90°F
CSI: 0.14

------------------------------------------
Test Results 07-18-2022 @ 12:07 PM
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Free Chlorine: 5.5
pH: 7.8
Total Alkalinity: 90
Calcium Hardness: 400
CYA: 60
Salt: 3000
Temperature: 90°F
CSI: 0.23

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Test Results 07-16-2022 @ 02:58 PM
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Free Chlorine: 3.5
pH: 7.3
CSI: -0.35

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Test Results 07-15-2022 @ 10:46 AM
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Free Chlorine: 3.5
pH: 8.2
CYA: 70
CSI: 0.51

 

[reggiehammond]

I'm sure you know how much faith the TFP community has in pool store results. None.

Don't overthink CYA. Trust your testing.
If your FC is holding in the heat of summer as you're expecting. It's fine.

If you're losing more FC than you expect, everyone can help you dig in further.

 

[jedigrover]

Trust your own tests. CYA is the most difficult test to perform, but with practice you can learn what to look for. I recommend getting tftestkits' CYA reference sample. It is a calibrated sample that you use in place of your pool water to practice the test and see what the answer should look like.

Based on your tests, things look pretty consistent except pH...looks like you must have added acid on the 15th to bring it down from being high.

Removing phosphates is really only insurance in case your FC goes to low, it can give you a slight (maybe a day) buffer in time to get things fixed before a bloom takes hold. The opinion here is that dead algae doesn't care how much food is in the water. Keep FC high enough to keep algae dead & you don't need to worry about their food supply.

The phosphate removers generally sold by pool stores are far less concentrated / effective than the ones you can buy elsewhere (Orenda or SeaKlear). Of course they are sold at an inflated price. I suspect it is a huge profit center for the pool stores and that is why they push it so much. When I first started as a pool owner, nobody had ever heard of measuring phosphates and using phosphate removers. Then it seems around 2005 or so every pool store everywhere started pushing them hard. It became the new bogeyman for everything wrong with your pool & only the pool stores had the solution.

 

[r2sie2]

I'm sure you know how much faith the TFP community has in pool store results. None.

Don't overthink CYA. Trust your testing.
If your FC is holding in the heat of summer as you're expecting. It's fine.

If you're losing more FC than you expect, everyone can help you dig in further.

This is my first pool and first time taking care of one. I do t really know how much FC I’m losing but I don’t think it’s much. I am having a hard time getting my FC high enough now that my cya is requiring higher levels. Do you know if it’s ok to run the salt generator 100% of the time? I’m worried that’s too much. I may just need to increase my pump run time I’m not sure yet.

 

[r2sie2]

Trust your own tests. CYA is the most difficult test to perform, but with practice you can learn what to look for. I recommend getting tftestkits' CYA reference sample. It is a calibrated sample that you use in place of your pool water to practice the test and see what the answer should look like.

Based on your tests, things look pretty consistent except pH...looks like you must have added acid on the 15th to bring it down from being high.

Removing phosphates is really only insurance in case your FC goes to low, it can give you a slight (maybe a day) buffer in time to get things fixed before a bloom takes hold. The opinion here is that dead algae doesn't care how much food is in the water. Keep FC high enough to keep algae dead & you don't need to worry about their food supply.

The phosphate removers generally sold by pool stores are far less concentrated / effective than the ones you can buy elsewhere (Orenda or SeaKlear). Of course they are sold at an inflated price. I suspect it is a huge profit center for the pool stores and that is why they push it so much. When I first started as a pool owner, nobody had ever heard of measuring phosphates and using phosphate removers. Then it seems around 2005 or so every pool store everywhere started pushing them hard. It became the new bogeyman for everything wrong with your pool & only the pool stores had the solution.

My kit came with a 50% buffer solution which I assumed was to be used in place of the pool water. I then added the solution and tested and it was completely clear. I know that’s wrong so I just kind of gave up on it. I’m going to try it again and see if I get anything different. I think I’ll ignore the high phosphates for now. May address it in the future. My pool is surrounded by organic dirt grass plants etc so I’m wondering if that may have an affect on that.

Edit: I just used the 50% CYA solution again and it did work, not sure what I did wrong last time. I think I may have been reading a little higher than what it really is. I also took my chlorine again and it is higher than my reading this morning. I don’t know getting a little frustrated. I think I’m going to start reading my FC more often and see if I’m getting big fluctuations. I also just added about 2 lbs of CYA I think that’ll get me to where I need to be

 

[reggiehammond]

I'm reading that the T-15 SWCG can produce 1.4 lbs of chlorine daily (running 24 hours, 100%.)

You can input that in the "effects of adding" tab of pool math app to see how much FC that should generate based on your pool size. Aim for 4 ppm or so, would be my guess.

 

[Katygreys]

If you have a K2006 or a TF100, then the Leslie’s machine is pretty much a random number generator. Interestingly, I have never seen a full blown K2006 equivalent in a pool store. In fact, before I purchased mine on Amazon, I called every pool store in Katy, TX and no one has one. Hmm wonder why that is. Also, why do they test water for free? Hmm. Interesting… Wait hold on, I think I see a black helicopter outside my window……

 

[jeffchap]

You have the most accurate test kit available. Stay away from the pool store and don't second guess yourself.

And forget about phosphates. Just another pool store scam to sell you something. Algae feeds on phosphates. If there's no algae present, the presence of phosphates is irrelevant.

 

[r2sie2]

You have the most accurate test kit available. Stay away from the pool store and don't second guess yourself.

And forget about phosphates. Just another pool store scam to sell you something. Algae feeds on phosphates. If there's no algae present, the presence of phosphates is irrelevant.

It’s funny you say that. He was like this is why you have algae present, I didn’t say anything because I was more curious than anything to see what the pool store would say after reading everything here. I suppose I’ll leave it alone, I just hate seeing the number so high haha. My water is ridiculously clear to look at, I felt attacked!

 

[r2sie2]

If you have a K2006 or a TF100, then the Leslie’s machine is pretty much a random number generator. Interestingly, I have never seen a full blown K2006 equivalent in a pool store. In fact, before I purchased mine on Amazon, I called every pool store in Katy, TX and no one has one. Hmm wonder why that is. Also, why do they test water for free? Hmm. Interesting… Wait hold on, I think I see a black helicopter outside my window……

I mean, I know you’re right. But it still bothers me lol. My water looks perfect though so I’m going to TRY and ignore it.

 

[r2sie2]

I'm reading that the T-15 SWCG can produce 1.4 lbs of chlorine daily (running 24 hours, 100%.)

You can input that in the "effects of adding" tab of pool math app to see how much FC that should generate based on your pool size. Aim for 4 ppm or so, would be my guess.

Thanks for showing me the effects of adding. I’ve always played with the numbers on the main page to figure that stuff out. This is really helpful. Made a small adjustment on the SWG we’ll see how it goes. Thanks again

 

[jark87]

I trust all of my own tests, except CYA. I don’t sweat it if I’m close to target, but I also get my water tested at Leslie’s just for the CYA. My local store is actually very good and their results are usually spot on with mine, so I trust their CYA results over my own. What I don’t do is listen to their advice. They don’t like that I keep FC in the 7-8 range and CYA around 70, but they don’t press the issue when I explain why.

 

[wireform]

Just so you know target FC is 5ppm for the 70 CYA you have. I like many here like to run that number + on the hot side like 7 for you so you never skirt danger falling too low. You can bring it up with liquid chlorine and find the happy setting on the SWCG to keep it there. You will also benefit from finding the same time every day to check your FC so you have what to base your adjustments on.

 

[jark87]

I like to keep FC at 10% of my CYA, so 7 is my target for CYA of 70. I’ve had my SWCG dialed in since early summer (50%) and haven’t had to touch it or add any liquid chlorine since. That’s really my CYA “test”. If FC is holding steady with a respectable SWCG setting, it’s doing its job.

 

[generessler]

I trust all of my own tests, except CYA.

Yeah. Been there. The suggestion about the R-7065 CYA Standard 50ppm solution is the key. Best $7 I ever spent. Just do a few tests with the standard to calibrate your eyes as to what it looks like as you fill from the 40 mark to the 50, and you're in business.