Chlorine Lock

[tam]

I am new to the forum I decided to reach out and ask online how to get rid of Chlorine Lock, this will be the second time this year this has happened. And Leslies always tells me drain pool half way. But I don't want to do this again, my CYA is reading about 100 my pool is AG about 12,000 gallons. Can I use household bleach to break my chlorine lock? and how much should I use? do I dilute it before I add? I am afraid of it hurting my liner. This is my 5th year with my pool and I go into lock every year this is frustrating, guess my Chlorine I am using has too much stabilizer in it, I live in Texas and it is really hot so I add about 2lbs of chlorine a week, a pound twice a week. Is this too much? Any help here would greatly be appreciated on how to get out of this lock without draining.

Also looking at converting to Salt Water next year.

thanks in advance.

 

[jblizzle]

Welcome to TFP!!!

You have found the right place. First, there is no such thing as "chlorine lock" that is just a term that pool stores use when they do not know what is going on and want you to drain water.

In reality, what you and the pool store do not understand is the relationship between CYA and FC (free chlorine). As the CYA gets higher, more chlorine is required to prevent algae from starting.

Your problem is very common. The pucks (trichlor) or the powder chlorine (dichlor) add both chlorine and stabilizer and are acidic so drive the pH and the TA down. The chlorine is consumed, but the stabilizer remains and builds up higher and higher which required more and more chlorine to prevent the pool from turning green. The pool store will tell you to add more powder which is just making the problem worse. Eventually they tell you to drain part of the pool (which is the only way to get the CYA down to reasonable levels.)

You can learn a LOT by reading up in Pool School (button at the upper right). Start with the basics:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

This shows the CYA/FC relationship:
pool-school/chlorine_cya_chart_shock

From here forward you have to commit to taking control. First by reading and learning and ditching the pool store and by getting yourself one of the Recommended Test Kits. Then if the CYA is truly too high, unfortunately, you will have to replace water to get it into the 30-50ppm recommended range. After that, you must only use liquid chlorine so no more stabilizer is added.

If you have further questions, please post them here.

 

[Bama Rambler]

Welcome to TFP.

I'll just ditto what JB said. Do some resding and take control of your pool yourself. You'll be much better off and should never have to drain water for so called "chlorine lock" again. Heck, you'll never even have to so called "shock" again.

 

[BoDarville]

Welcome to TFP!

Heck, you'll never even have to so called "shock" again.

Have not "shocked" my pool nor had to do a partial drain & refill since switching to BBB 2 years ago. tam, you can achieve the same results by switching to plain unscented liquid bleach as your chlorine source and maintaining the proper amount of FC according to your pool's CYA. It really is that simple.

Definitely would read the articles that jblizzle linked to in his post as well as purchase one of the Recommended Test Kits