FC and CYA Testing Questions

[Bicster]

I have some newbie questions here, please bear with me....

- When I'm testing for CYA, should I look at the dot with one eye or two - and how far away should my head be from the container? I find I can see it for longer with one eye, and obviously when I'm closer to the container - so how should I be doing this?

- I've seen folks talk about diluting pool water with tap in order to test for high CYA levels - can you do the same to test for high levels of FC? For example, if I had a kit that could only test up to 5ppm could I dilute the pool sample by 50% and then double the scale?

I have the Taylor 2006 - so the second question is hypothethical, but still interesting to me!

Bic

 

[aeh0603]

1) Test CYA outside in full sun. Turn your back to the sun so the tube is in the shadow of your body and hold it at waist level. Add a little testing liquid at a time and quickly glance in the tube (don't stare). When you no longer see the dot on first glance the test is done. If the door disappears between two lines round your result to the higher number. You can pour the liquid back and forth a few times to do the test again if you are unsure of your result.

2) Most municipal water contains FC and or CC but does not contain CYA. For that reason, you can't dillute the sample with tap water for the FC test, but you could use distilled water. Please note, dilluting your water sample adds an additional margin of error to your result so your result will not be as accurate.

 

[kevinskii]

Add a little testing liquid at a time and quickly glance in the tube (don't stare).

I'm a bit confused by this too. What you say makes sense, and this is how my pool guy does it, but according to the TFP extended test instructions for CYA, it seems like the black dot should not be visible even after staring for a while:

"6. Continue pouring until all traces of the black dot at the bottom of the view tube completely disappear, even after you stare at it for several seconds..."

 

[aeh0603]

I'm a bit confused by this too. What you say makes sense, and this is how my pool guy does it, but according to the TFP extended test instructions for CYA, it seems like the black dot should not be visible even after staring for a while:

"6. Continue pouring until all traces of the black dot at the bottom of the view tube completely disappear, even after you stare at it for several seconds..."

When I say don't stare, I mean don't watch the dot the entire time you are doing the test. It's important to look away and look back so that your mind doesn't play tricks on you where you think you still see the dot when you don't. You shouldn't be looking at it for more than a few seconds at a time (which is in line with what the extended instructions say), but you do need to look long enough to know if you see the dot or not ?.