CYA Test in TF-Pro

[TheFunk7279]

Hi all,

I’m a new pool owner and am working on dialing in the levels of my water. I inherited the pool from the previous owner and the original CYA level was very high. According to the pool store tests, it was at about 150ppm. So, I drained the pool and refilled.

To get the levels dialed in, I’m using the TF-Pro test kit. Now that the CYA levels have dropped I can effectively utilize the kits CYA test tube. However, I’m having trouble determining the actual CYA level. When I fill the tube, the black dot at the bottom of the tube becomes much less visible, but not invisible. It’s much more difficult to see than when the tube is empty, but it’s still somewhat visible.

I decided to take my pool water to two local pool stores to see what their tests determined. National Pools reports a CYA of 35, Leslie’s reports a CYA of 34. When I have the tube in my TF-Pro filled to 35, I can still see the black dot. As mentioned previously, its visibility is significantly reduced but still visible.

So my questions are, should I accept a CYA reading with the TF-Pro kit with visibility significantly reduced? Or, does the black dot at the bottom of the tube need to be entirely invisible to record an accurate reading?

Should I trust the consistency in the results from the two pool stores? Or, are those to be disregarded?

Any help is greatly appreciated.

 

[Bperry]

Hi all,

I’m a new pool owner and am working on dialing in the levels of my water. I inherited the pool from the previous owner and the original CYA level was very high. According to the pool store tests, it was at about 150ppm. So, I drained the pool and refilled.

To get the levels dialed in, I’m using the TF-Pro test kit. Now that the CYA levels have dropped I can effectively utilize the kits CYA test tube. However, I’m having trouble determining the actual CYA level. When I fill the tube, the black dot at the bottom of the tube becomes much less visible, but not invisible. It’s much more difficult to see than when the tube is empty, but it’s still somewhat visible.

I decided to take my pool water to two local pool stores to see what their tests determined. National Pools reports a CYA of 35, Leslie’s reports a CYA of 34. When I have the tube in my TF-Pro filled to 35, I can still see the black dot. As mentioned previously, its visibility is significantly reduced but still visible.

So my questions are, should I accept a CYA reading with the TF-Pro kit with visibility significantly reduced? Or, does the black dot at the bottom of the tube need to be entirely invisible to record an accurate reading?

Should I trust the consistency in the results from the two pool stores? Or, are those to be disregarded?

Any help is greatly appreciated.

Trust the kit over the pool store. How much CYA did you add and does it match what the kit is saying?

 

[TheFunk7279]

I haven’t added any CYA yet. I was working on reducing it by draining and refilling the pool. I might have removed too much in that process.

 

[Bperry]

I haven’t added any CYA yet. I was working on reducing it by draining and refilling the pool. I might have removed too much in that process.

Ah, i assumed you refilled the whole pool. If you can still see the dot at 35 that means theres less than 35ppm but note that the kit is designed to only give you useful info at the decade lines, 30, 40, 50, etc. filling in between makes the test take longer and doesnt give you any extra info because we always round the result upward. Just fill the tube up to each decade line and see if the dot is visible or not and I don’t make the test go faster and be just as accurate. The test has an accuracy of +\-10 ppm anyway, and the pool store has a much larger error tolerance.

 

[proavia]

CYA test

• Mix pool water and reagent as directed
• Outside, back to the sun
• Fill test tube to 60
• Hold test tube with only two fingers near the top of the tube
• Lower test tube to waist level and in the shadow of your body
• GLANCE into the tube - GLANCE, don't stare
• See the dot - fill to 50
• GLANCE into the tube
• See the dot - fill to 40
• GLANCE into the tube
• Don't see the dot - CYA is between 40 and 50 - round up to 50

The trick is to only GLANCE into the tube - outside with your back to thhe sun and the test tube at waist level in the shadow of your body.

 

[TheFunk7279]

Ok great, thanks! I’m going to try retesting now.

 

[TheFunk7279]

I just tried this testing method and can still see the dot at 30. I bought some Clorox stabilizer. I’m going to add via the sock method, aim for a 10ppm increase and see where that puts me.

 

[TheFunk7279]

CYA test

• Mix pool water and reagent as directed
• Outside, back to the sun
• Fill test tube to 60
• Hold test tube with only two fingers near the top of the tube
• Lower test tube to waist level and in the shadow of your body
• GLANCE into the tube - GLANCE, don't stare
• See the dot - fill to 50
• GLANCE into the tube
• See the dot - fill to 40
• GLANCE into the tube
• Don't see the dot - CYA is between 40 and 50 - round up to 50

The trick is to only GLANCE into the tube - outside with your back to thhe sun and the test tube at waist level in the shadow of your body.

After using the pool math app and sock method, I added a total of 2lbs 5oz over the last two days and I’m sitting comfortably at 40ppm CYA. Thanks for everyone’s help!