Chlorine tablets


New member
Apr 15, 2017
Camarillo, CA
I have been using Leslie's Chlorinator tablets in a floater in my 20,000 gal pool. They keep the chlorine at a level where I only sometimes have to add some liquid chlorine. But the pH gradually drops to where I have to add base (soda ash) to bring the pH back into the 7.4-7.6 range. If I then take the floater out of the pool and just use liquid chlorine, the pH does not drop. I have not had to add acid to my pool for many months. Is that a problem with those tablets? Should I switch brands or just stop using tablets.

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Hello and welcome to TFP! :wave: For daily use - I would stop using the pucks now. Tabs are not the worse thing to use, but only when you know your "true" CYA (stabilizer) level. Each tablet adds 6-9 ppm of stabilizer, so you can see that once you've gone through half a bucket of tabs, your CYA could be at a level that may require water change. So be careful. Normally, for typical daily use, we recommend the good old bleach, or the use of a SWG/liquid dispenser for those who have installed one. Also, tabs are a bit acidic which is why they drive your pH down which requires you to raise it again - rollercoaster ride.

If you don't have a TF-100 or Taylor K-2006C test kit, I would highly recommend you get one to test all of your levels (especially CYA) on your own. You have no idea how badly the stores do when testing CYA. In short, you can use tabs, but usually sparingly for only a short time before you have to change the pool water, so be careful.

Great to have you with us!


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

There is no problem using tablets as long as you keep your eye on the CYA level. If you let the CYA get too high the tablets become less and less effective about keeping the chlorine level up.

Once the CYA gets too high your only option is to drain some or all of the pool.

Tablets are some what acid, so they do tend to lower pH. About the only good thing I can say about them.. :cool:

Thanks for posting,

Jim R.


TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
NW Ohio
Welcome to TFP!

I only want to make one comment on Jim's statement, tablets are VERY acidic. This is why pools that use them typically use soda ash to raise pH because it also raises the TA. It is also why TA is best left above 100 for pools using tablets, to help counteract the constant addition of acid.

I have seen the results of using trichlor tablets without testing pH or TA. It ended in a heater being destroyed. Water was so acidic it ate right through the copper heat exchanger.

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