CYA reading odd

[Bellicusa]

Hello everyone.
That time of year again.
Opening the pool and trying to get an initial test out of the way.

Im using the TFTest Kit bought new 1 year ago.
Last year I had a CYA of about 35.
Drained no more than 1/3 of total pool capacity during closing last year.
Open pool this year and get NO reading for CYA. The water doesnt even look cloudy in the test tube.

Kinda nervous now...am I doing something wrong, is my reading wrong, testing stuff expired?

Dont wanna try to raise the CYA reading more just to find out I needed to replace the test kit.
Thoughts would be appreciated.

Anthony

 

[Bama Rambler]

If you stored the reagent inside it's most likely still good. Can you hold FC in it? If so how much chlorine did it take to get it to hold?

There are several reports of CYA going away over winter.

 

[duraleigh]

Trust your testing.....you almost surely have 0 CYA.

Draining 1/3 when you closed would lower 35ppm to about 20ppm and, depending on winter rains, etc. it would not be unusual for the rest to be unmeasurable.

I would plan on purchasing enough to get back to 35ppm.

PS - given reasonable care, the R-0013 reagent will last much longer.....in to next season.

 

[Bellicusa]

Thanks to both of you for the help.

The testing stuff was kept inside, so I will assume it is good.
I added 4 gallons of 6% an hour ago, so will test now to see what that gets me.
I was just trying to get the testing out of the way to determine what I was going to add.

I will plan on adding enough to get me back up to 35ish...and will chlorinate based on that number.

Edit:
Just tested...after 4 gallons of 6% and an hour of filter time I came up with 7.5 FC and .5CC
Lower number than expected...according to the pool calculator I should have ended up nearly 11.5 FC.

I will test again in the morning and see where I end up.

Thanks again.
Anthony

 

[Bama Rambler]

You probably had the CYA convert to ammonia and that's what got most of your FC you added. You may have to add a few times to get it to hold.

 

[Bellicusa]

You probably had the CYA convert to ammonia and that's what got most of your FC you added. You may have to add a few times to get it to hold.

Fair enough and could explain my drop to 5.5FC from 7.5 last night. Still getting .5 CC.
Will have to wait till tonight to get CYA. I'm sure most/all chlorine will burn off, but the boss doesn't seem to care

Thanks again.
Anthony

 

[XsAllOverIt]

You can also double check your CYA reading by making a 1/2 solution and see if the CYA drops in half, i.e. 1/2 pool water, 1/2 tap water.

 

[Txmat]

You can also double check your CYA reading by making a 1/2 solution and see if the CYA drops in half, i.e. 1/2 pool water, 1/2 tap water.

If the CYA is zero, half of zero is still zero.

 

[XsAllOverIt]

DUH! Oopsss!

 

[Txmat]

Been There Done That :lol: