Does anyone know if it is possible to get a false low CYA reading? I just shocked my pool with more dichlor than I thought I needed and my pool is still light green. I did a chlorine test and it reads zero and I did a CYA test and it shows virtually none. My pH is about 7.2. Any ideas?
CYA Testing
- Thread starter spaige
- Start date
How much dichlor did you add?
What was your CYA level before, or the last time you tested and when?
What is the water temperature? Did you warm the sample to room temp before testing?
Pool still green and FC zero? Sounds like algae ate up FC.
How much time between addition of dichor addition and CYA testing?...and was pump running the entire time?
Do you have a complete set of test results before you started shocking?
We'll help, but need more info
..........so many variables.....
What was your CYA level before, or the last time you tested and when?
What is the water temperature? Did you warm the sample to room temp before testing?
Pool still green and FC zero? Sounds like algae ate up FC.
How much time between addition of dichor addition and CYA testing?...and was pump running the entire time?
Do you have a complete set of test results before you started shocking?
We'll help, but need more info
..........so many variables.....I added 4 lbs of dichlor. I did not do a CYA test before so I don't know what it was before. I did not get the water to room temp. before testing. It has only been a couple of days since I added the dichlor but the pump has been running pretty much the whole time. I do not have a complete set of test results prior to shocking...
Sounds like I've made a lot of mistakes...but thanks for the help!
Sounds like I've made a lot of mistakes...but thanks for the help!
Situations like this are where the free testing at the Pool Store comes in handy.
Just sayin'
Just sayin'
CYA below 20 ppm can easily read as zero. You can use the pool calculator to calculate how much the cyanuric acid would rise for a given amount of dichlor. For your 30,000 gallon pool, 4 pounds of dichlor would raise your FC by 8.9 ppm and your cyanuric acid by 8.1 ppm.
If you go to the pool calculator, you first input your pool size in the "Size" box, up near the top, by the "Calculate" button. Then you go down to the "Effects of adding chemicals" section and input the number of ounces of the chemical you are adding (4 pounds = 64 ounces weight), and choose "dichlor". Then hit the calculate button, and the effect will show up in the box.
Butterfly said:
What is room temp considered to be? To clarify if I want to check my cya and the pool temp is 60deg what should be done? I've never let anything warm up before.
Well, the CYA test is more reliable when you let the sample warm up to room temperature first. For my purpose of "room temp", I just say to knock off the chill and 60º is chilly. Some of us just pull the sample and drop it in a cup of warm water to knock off the chill. Doing this first and allowing it to sit while you do the other tests gives it time to warm up a little before testing, which will make your testing more accurate. The CYA test is +/- 15 under normal conditions.bobby1017 said:
Hope this helps.
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