CYA Test Question: Dot reappearing?

[bostonpool]

Question on testing for CYA.

I've got the TF-100 kit and am trying to get "accurate" CYA readings.

I've poured in liquid before and the dot disappears and my level is at the 100 reading. But then 5 seconds or so later I can then see the dot again and I have to add more to make it disappear again. That brings me to 80ish.

Is it ok to add more solution from the squeeze bottle if the dot "reappears" after a few seconds?

 

[dkimble]

I have seen this too. Curious as well.

 

[pookiesunshine]

Try shaking the tube next time it happens. Also, dont stare at the dot, glance at it, then look away. does that make any difference?

 

[Richard320]

See if jiggling the view tube while at 100 makes it disappear again.

Sounds like the cloudy stuff is just settling out.

And if you are at 100, you could well be higher -- the graduations get really close together at higher numbers. You'll need to do the dilution test -- Step 8 -- to see what you're really at.

 

[Poolweekender]

I'm new to BBB - just a couple of months - and my biggest (and only) issue now is the same -- getting a reasonable CYA level.
When I first add solution to the tube, the dot may disappear because of the disturbance on the top of the solution level - but then reappears when the top of the solution level is flat.
So I think "shaking" or "jiggling" the tube may just disturb the top of the solution and help the dot disappear - I understand the point is to stir up the turbidity, but disturbance of the top of the solution may be a side effect.
I wish the basis of all of our calculations had a more reliable and accurate starting point - I am planning on ordering the CYA standard to try to do this better.
Cheers...