Please explain how to dilute CYA test if over 100

[Dreampool13]

Hey all!

My old neighbor just bought a home with a pool and he I'd trying to understand how to best care for his pool. Fortunately it seems like he hired a pool service that actually understands how high CYA can be detrimental to a clear sparkly pool. My neighbor said the guy tested it and CYA was over 100 and the pool tech recommended draining and using liquid chlorine once cya is under control.

My neighbor was surprised at first but when I gave him the same advice about draining the pool, he became interested. He's on his way over and he's either going to bring over a sample of water for me to test, or he's going to borrow my CYA testing supplies.

I've read up on how you can dilute the cya test with distiller water, but could someone explain it to me like I'm a 10 year old? Do I add half tap water/half pool water to my red tipped bottle, then top it off with my cya testing solution? Do I mix it somehow in a Pyrex measuring cup? It must be simple but I'm just not getting it. Please help! He's going to be here with in hour.

- - - Updated - - -

OMG. So many typos. Forgive me, I'm on my phone.

 

[pwrstrk]

Please explain his to dilute CYA test if over 100

Use half tap water half pool water and fill to the bottom of the label of red tipped bottle. Then fill to the top of the label with the reagent. Shake to mix wait 30 seconds. Shake once more. Pour into the view tube. When black dot disappears take your reading then double it.
If your pool water is cold let warm to room temp. Cold water can sometimes affect the test

 

[jblizzle]

Re: Please explain his to dilute CYA test if over 100

Add pool water to bottom of sticker.
Add tap water to top of sticker.
Shake.
Pour out half so mixture is to bottom of sticker.
Add reagent to top of sticker.
Shake.
Test outside with back to sun and tube at waist level.
Pour back and forth a few times to see if you get the same result.
Double the result.

 

[Dreampool13]

Re: Please explain his to dilute CYA test if over 100

Thank you that's exactly the info I needed.

 

[FLAK111]

Is this process the same with the "dot" test? basically, take a water sample, dilute with 50% tap water, shake for 30 seconds, pour slowly into dot test tube until dot dissapears. result times by 2 for actual. Sound right?

 

[triptyx]

Flak - this is the dot test for CYA that is being discussed, yes.

You want to swirl rather than shake the sample - this will prevent extra cloudiness due to small bubbles that may form when the sample is shaken. So dilute your sample, add reagent, swirl vigorously, let it sit 30 seconds, swirl again, then pour into the tube.

Remember to always round up. If the dot is visible at 40 and disappears at 30 (I pour to the lines, I don't mess around with trying to read in between the gradations), call it 40ppm.

 

[mteator]

When my CYA was up in the 3 digits, I would usually take a cup of pool water and a cup of tap water (or three cups when i was diluting 3:1) and mix them, then I put that diluted mixture into the test container up to the mark. This was easier to get the ratio dilutions I was looking for. My CYA was 400+, so 1:1 dilution wouldn't cut it down enough. It took a whole summer of partial draining and rain to get me down to a somewhat reasonable level. With 1:1 I'd multiply the answer by 2, with 2:1 multiply by 3, with 3:1 multiply by 4, and so forth.

Being that it was so high, I wasn't looking for absolute accuracy, but getting feedback that the number was going in the right direction made me feel better.

 

[tim5055]

In the past we may have recommended further dilutions from 1:1, but history has shown that even a 1:1 dilution introduces error into the computation.

Further dilutions introduces errors that are just too high to make the test results more than a "guess".

 

[mteator]

Further dilutions introduces errors that are just too high to make the test results more than a "guess".

Thanks for the additional information!

 

[YippeeSkippy]

I always advise folks to just mix 1:1 pool and tap water (no quantity given, just assumed they'd figure that out) and mix it in a cup or something then use this mixture to fill the bottle to the bottom of the label.

I dislike the idea of having them try to accurately measure it as they're adding it to the bottle. It seems ripe for errors to me.

I'm too OCD for that.

Maddie

 

[FLAK111]

I always advise folks to just mix 1:1 pool and tap water (no quantity given, just assumed they'd figure that out) and mix it in a cup or something then use this mixture to fill the bottle to the bottom of the label.

I dislike the idea of having them try to accurately measure it as they're adding it to the bottle. It seems ripe for errors to me.

I'm too OCD for that.

Maddie

HAHA.....ditto. Thank you and everyone else for the advice. I diluted and found to be in the 180-200 range. Waiting until April 1st to drain/fill 50% of pool as my water sewage rates at that time are locked in for the year and a refill wont effect it. (((thank God I called the Water Company and found that out! )