Raising free chlorine level


New member
Apr 22, 2017
Hello! This is my first pool. It is an 18' round above ground. Sand filter. Filled the pool in mid April, I live in Pennsylvania so we've had some warmer than usual days, but recently below average. About two weeks ago, my ph needed to be increased and also the free chlorine. I added the recommended solution from our pool store and then shocked the pool. Everything was good for about a week. Now the free chlorine is low again, but everything else is good. I have a floating chlorinate. Do I have to shock again? Or should I be adding my chlorine in another way? Thanks in advance!


LifeTime Supporter
TFP Guide
Apr 2, 2012
Columbia SC
Hi and welcome to TFP :)

How are you testing your water? We reccomend testing with a good home drop based test kit. Like these

Pool School - Test Kits Compared

Also, have you had the chance to look at any of the articles in the Pool School link at the top of the page? By using a chlorinator with pucks, you are also adding CYA which can get too high over time and make your chlorine much more difficult to manage. Here is a link to some basics.

Pool School - ABCs of Pool Water Chemistry

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