CYA Might be High

Mar 10, 2016
16
Fort Worth tx
#1
Pool is less than a year old and have always used liquid chloring and only tablets when on vacation. What else can cause the CYA to rise, if my test was accurate? I ran out of the CYA reagent, so I am ordering more. Not even sure what the actual measurement was since it was below the 100 mark.

Test Results today:

FC 4.5
CC 0
PH 7.6
TA 75
CH 300
CYA Halfway from the bottom and 100 on the K2006 test and black dot is gone.
 

pabeader

LifeTime Supporter
TFP Guide
May 14, 2015
4,349
Cartersville Ga
#2
Any powdered/solid type chlorine can contribute. Depending on how many tablets you used, it can take a short time to get into trouble.

Also. there is always the chance that it was just simple testing error.

I was at Walmart the other day and noticed that they had the 6-way test kit that includes CYA. In a pinch that might work for you.
 

Patrick_B

TFP Expert
LifeTime Supporter
Jun 7, 2011
14,999
Midland TX
#3
There are other forms of solid that don't contribute Cya, those being Cal-Hypo, and Lithium bound Chlorine but the latter is far less commonly used due to cost. Still pabeader is right that other bags, boxes and such are the likely culprits.

Your Cya test was accurate, or likely close enough that it doesn't matter. Cya can build much quicker than most people imagine so don't doubt it too much as it wouldn't be surprising.
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
10,954
Houston, Texas
#4
It is best to make sure the pump has been running 15-30 minutes before pulling your test sample. There is some debate if water temperature affects the test result, so you may want to let the sample warm up to a least 70 degrees to help with accuracy. Also make sure you read the result in bright sunlight with the sun at your back if possible.
 
OP
OP
T
Mar 10, 2016
16
Fort Worth tx
#6
Last test was end of summer, water temp is below 70. I have only used tablets twice since pool was built. Nothing other than bleach or liquid chlorine and acid have been used in pool.
 

Patrick_B

TFP Expert
LifeTime Supporter
Jun 7, 2011
14,999
Midland TX
#7
That doesn't seem to match your Cya results unless I misunderstood you. Let's see what you get after you run a new one when you are re-supplied.