TIL- Chlorine pucks/tabs go bad

[Water Cat]

So for the past couple weeks my chlorine levels have been abysmal no matter how many tabs I put in. I shocked a week ago and chlorine was better next day. Fast forward 3 days and the level is back at 0. I put 10 tabs in the chlorinater set it at it's highest setting and put another 3 in the basket. This is more than double what I usually put in, pool should be off the charts right? Wrong, the test still shows 0.

I then find out the tabs I have been using are 10 years old and where tucked away in the back shed until we cleaned it out 3 months ago.

I bought a new jug of tabs.

I then cleaned the old tabs out of the pool and put 5 new ones in the chlorinater And the next day chlorine is back up to normal range, water is crystal clear and nice on the skin again and has been ever since.

Who knew? Chlorine tabs go bad.

 

[Cwiggs]

Are you sure you don't/didn't just have some algae or ammonia in your water? Might want to do an OCLT?

10 years is a long time but I wouldn't think trichlor tabs would be 0% effective after 10 years; assuming they were kept dry and out of the sun.

 

[Donldson]

Hmmm, no, not really. Pucks don't go bad, you can even dry them out and store them after use. I've used pucks nearly that old with exactly the results expected.

I'm sure there's more going on here, but without testing data from reliable sources there's no way to say what it is.

 

[Mdragger88]

Hey, WaterCat!
I agree that perhaps u need to do an Overnight Chlorine Loss Test to rule out algea especially since you’ve had some time @ 0.
Whether or not the tabs were totally ineffective. I’m sure it’s possible their potency was compromised some.
Tabs aren’t really recommended here for daily chlorination due to the likelihood of high cya build up as well as the effects they can have on ph & subsequently TA. Most try to reserve their use to vacations etc. & use liquid chlorine or a swg for daily chlorination.

How to Chlorinate Your Pool

Before chlorinating your pool, you should know these simple tips. Learn the best way to add chlorine to your pool.

www.troublefreepool.com

 

[CraigChing]

Your signature doesn’t show how you test your water. Before going any further, get a TF-100 or Taylor K2006c test kit and verify your chlorine using the FAS-DPD test that comes with those kits.