CYA question...

[NjPool84]

Hi,

Just a general question:

Does it matter what background/surface and how much sunlight you test your CYA in? And since we are here, all tests?

Just tested my CYA in total sunlight, on a glass table using the taylor test kit. Dropped in the solution until the black dot was totally gone, reading was 40.

This was done correctly, I would imagine, yes?

Thanks,

 

[domct203]

Hi,

Just a general question:

Does it matter what background/surface and how much sunlight you test your CYA in? And since we are here, all tests?

Just tested my CYA in total sunlight, on a glass table using the taylor test kit. Dropped in the solution until the black dot was totally gone, reading was 40.

This was done correctly, I would imagine, yes?

Thanks,

Lighting is especially critical with the CYA test, more so than any other sans pH.

When checking CYA, it should be on a bright sunny day, midday sun is best. You should have your back to the sun, and hold the viewing vial at about waist level with it in the shade of your body. Hold the tube with just two fingers at the very top, trying not to block the indirect light from illuminating the vial.

I find it easiest to fill the vial to a value that I know is higher than actual, glance for the dot, fill to next value and glance again, repeat until the dot is gone when I glance at the vial. Don't study the thing looking for the dot, you will just go insane LOL.

 

[NjPool84]

Lighting is especially critical with the CYA test, more so than any other sans pH.

When checking CYA, it should be on a bright sunny day, midday sun is best. You should have your back to the sun, and hold the viewing vial at about waist level with it in the shade of your body. Hold the tube with just two fingers at the very top, trying not to block the indirect light from illuminating the vial.

I find it easiest to fill the vial to a value that I know is higher than actual, glance for the dot, fill to next value and glance again, repeat until the dot is gone when I glance at the vial. Don't study the thing looking for the dot, you will just go insane LOL.

Haha. Interestingly, I will look with both eyes and then close one eye. And yes, it can drive you crazy.

And this is good information to know, because the two other times that I tested CYA in the last month, it was either on a cloudy day, or a nice day but in the shade. And my CYA was slightly elevated. I could re-test just to make sure but you use so much reagent in one test that I don't want to run out and have to buy more. Considering that my PH is good, FC is acceptable, crystal clear water, and I skim 1-2x a day and vac every other day...I'll wait a while. Maybe mid july re-test in the sun if I don't see any issues before then.

 

[spinPHD]

Yep, the key is consistency with the CYA test. If you always use domct's technique you get more comfortable with CYA test.

 

[rmturner54]

You can retest more than once with the same test .

 

[domct203]

Also, you can pour the sample back into the mixing bottle and run the test again. I usually do this 2 or 3 times to make sure that I am comfortable with my result.

 

[rmturner54]

Yep..what i said, only better

 

[domct203]

LOL, great minds think alike!

 

[JVTrain]

CYA test should be done in full sunlight. Tube held in front of you at waist height. Sun behind you. The key is lighting consistency.

Sent from mobile device. Beware of brevity and grammar errors!

 

[LeMuttman]

How hot is too hot to test? I thought I read temp played a key in getting accurate test as well.