Can't tell if my chlorine tester is bad?

[garywi]

First time experience since we had pool over 7 years. Went out to swim and was overwhelmed by smell of Chlorine. Thought it was over chlorinated. Took out my floating chlorine tablet floater for a week now. In sunny, hot Arizona, the water is still testing like this in photo. I still think its over chlorinated based on this test, but the smell is gone. I don't think its under chlorinated as there is no algae anywhere, not even in my shallow spa. Not sure if my tester is wrong?

 

[mknauss]

The OTO test you are using reads Total Chlorine. If it smells, it is primarily CC. Which is not good.

You need a proper test kit. I suggest the TF-100 A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.

 

[garywi]

Thank you. My smell is gone. I've used this test for several years and it would show some shade of yellow. Now all red. Is the water still over chlorinated.

 

[mknauss]

That color implies the TC is well above 5 ppm. Unknown what level.

 

[Griswald]

You cannot tell if pool water is over or under chlorinated without knowing what the CYA level is.

The 2 are related to each other.

 

[garywi]

Seems odd. It's been 115 F in AZ all week and the chlorine level is not down. If no smell, is it safe for kids to swim?

 

[mknauss]

Without knowing the CYA, we have no idea. If you have been using trichlor, most likely your CYA is very high, so you need a high FC. But without data, we cannot provide guidance.