CYA Test Directions...Update?

Apr 10, 2018
310
Rancho Cucamonga, CA
#1
I've read a few threads mention that water temp plays a role in the accuracy of the CYA test. Since CYA levels are critical to proper pool maintenance, maybe the test instructions can be updated to include a note regarding cold water samples. I'm not sure if this is possible, but it may help new users achieve accurate results.

Just my 2 cents...

Mike.
 

duraleigh

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Apr 1, 2007
31,271
Sebring, Florida
#3
I am not completely sure but I think, over time, we have exaggerated that affect.

Certainly, we would not rely on a test in 40 degree water but we probably shouldn't be testing when the water is that cold anyway.

So, as we begin to open our pools in the spring, we see water temps somewhere around 55-65 degrees......give or take. I doubt the CYA test will be skewed by that variance any SIGNIFICANT amount. I do not believe room temperature will give a much different reading than the normal pool temp.

The only way we could get an indicator right now is if some of our Minnesotans (or Canadians) with water temps still in the 50's is to do the CYA test at regular temp, then do it again after warming the sample to 75.

Any volunteers? That would be a worthwhile experiment.....not very scientific but it would be a good indicator.
 

Divin Dave

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Oct 2, 2013
5,185
Longview, Texas
#4
I totally agree with Duraleigh.

The CYA/FC is most important so algae doesnt get hold of us. With the lower water temps, its very slow for algae anyways, so the variation in temps isn't a big deal IMO.
 

jblizzle

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May 19, 2010
41,197
Tucson, AZ
#6
What actually happens when the water is colder is that the reaction with the reagent is slower. So you may need to wait more than the minute or so that is recommended in the instructions for the reaction to complete to get an accurate result. Whether you let the water warm up or you just wait longer after mixing the reagents, you should likely get the same result
 

kimkats

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Jul 11, 2012
35,551
Tallahassee, FL
#8
HOw about if I put some pool water in the freezer? I do have regent but think it would be better if the "water" is cold as if coming from a cold pool. Will report back after I play with it.
 

borjis

LifeTime Supporter
Aug 19, 2014
2,634
Pacific NW
#9
This year, I definitely noticed my pool water sample tested at 60F, cya was not registering at all. (cya reagent was stored inside/room temp)

The very same day, that same sample at 70F registered as cloudy and CYA of 30.

So that's how I am doing pool opening CYA test from now on.

Previous years I had not noticed because I did the CYA test after the heater had
brought the water to at least 75F.

And the only reason I tested it cold this year is because a very thin film of algae
started up and I needed to know what it was to SLAM.

I had not added the first chlorine of the year beginning of march like I usually do (waited til first of april), a mistake I won't make again.
 

BasicTek

Bronze Supporter
Oct 9, 2016
801
Lake Mary, FL
#10
Anybody got some CYA standard to toss into the freezer for a hour or so?
I still have some I bought form TFP last summer. Now I tested over the summer and got 40-50 so I figured that was about what I should see, I tested it this winter (stored at about 75 in home) and it tested more like 50-60.

What do we expect cold water to do vs room temp? To send the reading up or down?
 
#11
I still have some I bought form TFP last summer. Now I tested over the summer and got 40-50 so I figured that was about what I should see, I tested it this winter (stored at about 75 in home) and it tested more like 50-60.

What do we expect cold water to do vs room temp? To send the reading up or down?
It (possibly) gives a lower reading then "actual"/expected
 

kellyfair

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Jun 30, 2016
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Tampa, FL
#13
Someone in a recent thread experienced a difference when they allowed their sample to warm up. Unfortunately I cannot remember who it was!
 

BasicTek

Bronze Supporter
Oct 9, 2016
801
Lake Mary, FL
#14
my pool is usually tested around 90 degrees and my CYA seems to always be a bit lower than I think. I only test it ever few months but I keep loosing 5-10 a month rather than the more expected 3-5. I'll test this sample around 40 (wherever my fridge is set, it was 60 2 months ago at 75. Maybe there is enough for a couple other tests as well