You'll find that there is no such thing as "Chlorine Lock". It means that your stabilizer (CYA) level is far higher than we generally recommend and regular levels of chlorine won't keep your pool sanitary. However, with the test kit we recommend (an FAS-DPD chlorine test kit) you can measure much higher chlorine levels and still swim safely and comfortably.

"Chlorine Lock" is a direct result of excessive use of chlorine tablets and "Di-Chlor" powder, both of which release massive amounts of stabilizer even when you don't want anymore.

You CAN use these chemicals without getting into the situation called "Chlorine Lock" but that involves regular testing of your pool water. I test for stabilizer (CYA) levels every single week. That way I know how to compensate.

Carl