Chlorine: Liquid vs 3in pucks


Gold Supporter
Jan 28, 2018
Hello all! I got my house w/ this pool May2017. I quickly became a DIY'er for my pool needs based on how expensive hiring a pool person was. I've learned alot! I've been using Shock and 3 inch pucks. I have seen random post on TFP about liquid chlorine. Can anyone expand upon the liquid vs the pucks? Please see my type of pool in my signature to see what may be best for my pool. All I know right now is to use the pucks in the skimmer baskets....sounds easy enough and it has been, but if liquid is cheaper / easer, then i'm willing to change my ways! thanks in advance.

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Can anyone expand upon the liquid vs the pucks?
Remember, products like tablets/pucks are not just chlorine, they also have a considerable amount of stabilizer. It is that stabilizer that once dissolved, does not leave the water except for a very small amount. In short time, those products cause the CYA to exceed a reasonable level and often times causes owners to drain/replace some of their water. Regular bleach, like the Great Value at Wal-Mart or Bravo at HEB, are perfect for increasing the Free Chlorine (FC) level in your pool as long as you refer to the Chlorine/CYA Chart (link below) and ensure it matches your current CYA level. Plus, bleach has no ill side effects like tablets do. Regular bleach is the same as liquid shock or chlorine - sodium hypochlorite. We're not saying you can never use pucks/tabs, but you must know what yoru current CYA level is and how long you can use the tabs before the CYA gets too high. You can learn more about TFP-recommended products in the Vital Links below in my signature. Hope that helps.


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

You should never put pucks in your skimmer unless your pump is running 24/7. If the pump shuts off, over time the pucks can 'rot' the plastic skimmer basket...

Using pucks for a long time will continually increase your CYA level to a point it will be almost impossible to keep enough FC in your water to prevent algae...

See this chart... [FC/CYA][/FC/CYA]

Notice how much FC you need as your CYA levels get higher.

Using pucks is just fine if you monitor your CYA and ensure it does not get over about 50 in our area.. The only way to reduce CYA is to drain at least part of your pool water.

If you are using Powdered Shock, it also increases your CYA..

My pool is almost 4 years old and I have never added a single bag of Pool Store Shock.. Following the TFP process, it is just not needed.

The key to the TFP process is have the right test kit and testing your own pool water, as well as maintaining the proper CYA to FC relationship...

Thanks for posting,

Jim R.


Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
East Texas
I have seen random post on TFP about liquid chlorine. Can anyone expand upon the liquid vs the pucks?
I remember seeing those couple of stray posts too. Couple meaning a couple hundred thousand or so! We kinda believe in it around here you might say. The previous two Moderators gave you excellent advice. Soak it up and enjoy.