Newbie learning to test water....

Rost-Lufer

Well-known member
Jun 26, 2023
62
Southern Michigan
Pool Size
7500
Surface
Vinyl
Chlorine
Liquid Chlorine
Hey Y'all,

Just got our first pool up and running a week or so ago. Have the TF-Pro test kit. Did some tests and have a few questions....
PH-7.5
FC-2.5
CC-0-.5
TA-70
CYA-about 40

The chlorine side of the PH test block is just there to show presence of chlorine, correct? The directions say this test should be done daily. Reading on this site it seems that you should be doing the FAS\DPD test for chlorine daily to get an accurate reading. Does PH need to be tested everyday? And if doing the FAS/DPD test everyday it seems the chlorine side of the test block is useless.

CYA test. Is it best to do this with a light underneath the tube? Or just fill the tube up, and when the dot disappears call it good? This test seems a bit tricky, especially with my bad eyes!

Also, if I understand correctly, anytime the test is supposed to change color, I need to add a drop even if it's barely noticeable and faint? So faint I wonder if I'm imagining it.

As for my test results, any recommendations? I'm going to add 3 cups of 10% CL to bring my FC up to 5, according to pool math based on the CYA level.

Thanks again for everyone's help! This site has been great for a newb!
 
The chlorine side of the PH test block is just there to show presence of chlorine, correct?
Correct.

And if doing the FAS/DPD test everyday it seems the chlorine side of the test block is useless.
Also correct. :)

CYA test. Is it best to do this with a light underneath the tube? Or just fill the tube up, and when the dot disappears call it good? This test seems a bit tricky, especially with my bad eyes!
I'll add some notes below for this one.

anytime the test is supposed to change color, I need to add a drop even if it's barely noticeable and faint? So faint I wonder if I'm imagining it.
Add drops until the color change stops. Add one more drop if needed to be sure then just don't count that last drop.

As for my test results, any recommendations? I'm going to add 3 cups of 10% CL to bring my FC up to 5, according to pool math based on the CYA level.
Chlorine yes!
 
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The chlorine side of the PH test block is just there to show presence of chlorine, correct? The directions say this test should be done daily. Reading on this site it seems that you should be doing the FAS\DPD test for chlorine daily to get an accurate reading.
At the start do the FAS-DPD every day. Soon you will understand what the pool needs. Then if you do not have time, do the OTO (yellow) one just to check that chlorine is as expected.
Does PH need to be tested everyday?
Likely not in your pool. You do not add a lot of fill water so test it every few days and see if it changes.
CYA test. Is it best to do this with a light underneath the tube? Or just fill the tube up, and when the dot disappears call it good? This test seems a bit tricky, especially with my bad eyes!
When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....
 
This may help you.

CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. If it helps, pour a little, look away, then look back and pour some more. Some people like to squirt enough solution to go line-by-line for a better feel. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading. If you are still questioning your own results, have a friend or two do the same test 2-3 times. Share your results only after everyone is done to see if you came up with the same average results.
 
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The OTO chlorine test is anything but useless. While it is not particularly precise, it shows the presence of chlorine and the intensity of the yellow indicates just how MUCH TC you have.....just not as accurate as we often like or need.

So imagine this scenario........You decide that you will check chlorine each day by using the OTO comparator block. For the first 4-5 days it is a medium yellow.....indicating around 3 ppm. The next morning it is a light, weak yellow and tells you very clearly that your chlorine level has changed,

Now, you do the FAS/DPD test to see exactly where your chlorine is and what, if anything you will do about it. Once you have solved why the chlorine has changed you can then return easily to using the OTO test daily to monitor chlorine and detect any changes.

Doing this routine with ONLY the FAS/DPD test is just fine if you have the time, The FAS/DPD takes a few minutes and the OTO takes 15 seconds. The FAS/DPD is probably 10 times more expensive in chemistry consumption as well.

Everyone develops their own methods and preferences but TFP teaches the value of the OTO test.......it's your call whether or not to use it.
 
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CYA test. Is it best to do this with a light underneath the tube? Or just fill the tube up, and when the dot disappears call it good? This test seems a bit tricky, especially with my bad eyes!

CYA test - What to Look For
 
You already got the best answers but I'll add my $0.02 ...

As mknauss mentioned, as a newbie or at pool startup (for me) watch the water carefully then not as much. You learn what your water is doing with how you are using your pool. At some point you may test every few days and actually know to add chlorine before hand when an event - company or a storm - happens to offset the extra load on the pool. It kind of becomes second nature once you get the swing of it. Also, if using liquid chlorine you'll get the hang of just putting it in the pool from the jug, you'll know how many "glugs" you need to be about the correct dosage.

It gets easy to take care of a pool once you "get it"!
 
One more tip*
While you’re getting the hang of things (even thereafter) dose to high target for your cya FC/CYA Levels
This will ensure you have plenty of wiggle room with fc in case of a high uv/heavy bather load day etc. & you don’t risk falling below minimum.
 
One more tip*
While you’re getting the hang of things (even thereafter) dose to high target for your cya FC/CYA Levels
This will ensure you have plenty of wiggle room with fc in case of a high uv/heavy bather load day etc. & you don’t risk falling below minimum.
YES! Wiggle room is good!! Considering it is safe to swim in SLAM levels of chlorine don't try to minimize the amount you swim in ... clearing a green pool is the pits, swimming in 2-3 PPM extra chlorine is worth it!!
 

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Fc 3
Ph 7.5
Ch 100
Ta 44
Cya 30

Forgot to test CC. I added 30oz. 10% bleach based on target of 45 for cya and wanted to add 15oz cya to bring levels up to 45 but only had 12.5oz on hand. Should I bring TA up to ideal levels?
 
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