Can't tell if my chlorine tester is bad?

garywi

Bronze Supporter
Jul 12, 2013
90
Phoenix, AZ
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?
 

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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,053
Laughlin, NV
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

Bronze Supporter
Jul 12, 2013
90
Phoenix, AZ
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

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,053
Laughlin, NV
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.