What to do about chlorine lock?

[Vinny]

My tub has chlorine lock ... I had it on my last water change and it was determined by Stuart - Thanks Stuart!!

But, I have new water about a month old and it seems that it has developed it again.

What can be the cause of it?

I use dichlor, run ozone 10 hours a day and my when my tub clears it's pipes I have it injecting air. I do use a foam thermal blanket and the tub only gets used once or twice a week.

To give an example of what's happening - I used the tub last night, soaked for about 50 min and added what should have been 2 PPM (even if I slipped, it would be 3 PPM). Now 20 hours later I have 3 PPM chlorine verified by 2 test kits.

I'm at a loss at what's going on unless my tub is the most cost effective tub in the world when it comes to chlorine ... or maybe it thinks I'm putting in bromine!

As long as I'm not doing any damage to the tub, I really don't care but would like to know, at least I don't have to worry about bacteria!

[wmccall]

Stuart didn't explain this condition to you on April 1st did he?

[Vinny]

Ya know it could have been!

[Dr. Spa™ Ret.]

Is that 3ppm, total combined chlorine or Free Available chlorine?

[Vinny]

That's free available chlorine.

[Vinny]

Is that 3ppm, total combined chlorine or Free Available chlorine?

Hey, I just got what you're insinuating!!!

[Drewski]

Perhaps this quote from a water quality page could help (underlining added)?

"What is TOTAL, COMBINED and FREE Chlorine?

...these are states of existence for the chlorine molecule. If a molecule is free, it has not bonded with or combined with another compound. It is therefore available for sanitizing. When free chlorine molecules encounter and destroy a nitrogen or ammonia containing compound, they combine with them to create a combined chlorine compound, or a chloramine. The chloramine is no longer available to sanitize anything, and it floats around in the water, blocking the path of those do-gooder free chlorine molecules, and stinkin' the place up! If you smell a strong aroma of chlorine in and around a pool, chances are it has high combined chlorine levels. This level can also be tested with a DPD test kit which measures total and free levels separately and allows the tester to determine combined levels by subtracting the two. Total chlorine is simply the sum of combined and free levels."

Me thinks you worry too much my friend?

Drewski

[Vinny]

No worries Drewski!

I have to wonder what it means when someone is asking is it combined chlorine AFTER you get out and added chlorine ... I was thinking that Doc thought I was stinking the water up!!!  

[Vinny]

At least I have the most sanitized tub on the planet!