Pool tests of PH changed color

[Masspools]

Hi All

I have tested the pool water at commercial pool using our standard test kit. The reading from PH registered as 7.4, then the color of the tested water gradually changed to purple. Why would it do this?
Thanks
James

Salt pool
34,333 gallons
ORP 840
Cl 5
83 degrees
Clear

Update: people have mentioned there lips are burning and rashes.

 

[jblizzle]

Here are some extended instructions:
extended-test-kit-directions-t25081.html#p206394

The pH test should be read immediately and then it is not uncommon for it to drift up. FC > 10ppm can also make it drift up.

What test kit are you using? Looks like your CL is at the top of your range probably right?

We would need a full set of test results to better guess at what is going on:
pool-school/read_before_you_post

 

[JasonLion]

I suspect that your FC level is very very high and you are not using CYA.

An ORP of 840 is exceedingly high. Plus, the PH test turns purple when the FC level is very very high, typically at FC levels over 20.

Most likely the high FC level is the result of using a SWG too much on an indoor pool.

 

[PJ]

I agree with everyone else. What does your free chlorine read? If it begins to turn pink and then nothing....it is way too high.