Liquid Chlorination as a Sanitizer ... Use as Shock too ?


New member
Apr 19, 2018
Muskego, WI

New to TFP. Been reading a number of threads (older) that there are advantages to using Liquid Chlorine as a sanitizer vs trichlor sticks or dichlor tabs which play havoc to CYA. Every year my CYA increases significantly around mid July and its a challenge til end of swimming season. I have been using Ultima Total Control which has Dichlor in it so I suppose I am double whamming the CYA problem.

I would like to try something different this year ...

I know the disadvantage of liquid chlorine is the INconvenience of the gallon containers. I do have a solar cover which I use daily here in Wisconsin (gotta keep that heat in as long as possible here in the north) so I am curious if .5 gallon of liquid chlorine every couple days would be sufficient? Also .... when I need to shock the pool because the Combined is high ..... what do I use then to shock the pool ? Just more gallons (4) of liquid shock?

1998 16x32 22k IG Vinyl Liner Sta-Rite S3 Cartridge filters

Hope to hear.



LifeTime Supporter
TFP Expert
Apr 17, 2007
You want to use liquid chlorine to SLAM a pool. How much depends on your CYA. You can find all that info in POOL SCHOOL and start by reading the ABCs of pool water chemistry and look at our recommended test kits.


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

Welcome to TFP... a great place to find the answers to all your "Shocking" pool sanitization questions... :shark:

Bottles of Bleach, Liquid Chlorine and Liquid Shock are all the same thing, they just have difference strengths.. Bleach is usually 6 or 8.25%, Liquid chlorine and Shock are just 10 or 12.5%

Sounds to me like you are used to dumping in powered Pool Store "Shock" every week or so... With the TFP pool care process, this is just not needed. Basically, if you maintain your FC and CYA at the proper relationship, that is all you need to do. I have never added weekly doses of anything to my pool!!!

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

In a 22K pool, a 121 oz. jug of 8.25% bleach will increase your FC by 3.6 ppm. Most pool use 2 to 4 ppm of FC per day. A pool with a solar cover would use 1 to 2 ppm a day.. Removing your cover for a couple of hours every other day should allow the sun to burn off any CC's.

Thanks for posting,

Jim R.


Mod Squad
LifeTime Supporter
TFP Expert
May 11, 2014
Franklin, NC
Welcome to TFP!!:handwave:

As others have implied, you have fallen in with a group of folks who don't believe the "traditional" methods of pool care (float tabs and "shock" every Saturday) are the way to go.

So, how do we differ? We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. To do that you need your own accurate test kit.

Why your own test kit, the pool store does it for free? Not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. Plus, logic and common sense asks the question, do you take advice from someone who has a financial interest in the answer given. Go into a pool store and ask if you need to add anything to your water; what do you think the answer will be?

If the pool store won't work, how about test strips? Basically, the strips simply do not provide the accuracy and consistency you need. Around here we call them "guess strips".

To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. All the kits that we recommend have this test, while very few other kits do. The kits sold at the pool store generally won't won't cut it, but be careful pool store employees are known to say “it's the same thing”. Generally it's not! I recommend the TF100 as it was designed for residential use and has more of what we do use and less or none of what we don't use often.

The only other real option for a test kit is a Taylor K-2006. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.

I also have the SpeedStir and Sample Sizer. They speed testing and accuracy.

To follow the pool care methods taught here you need to arm yourself with the knowledge and tools necessary to care for your pool. Well, I covered the most important tool - the test kit. But what about the knowledge.

The knowledge is condensed in the Pool School link at the top of every page. It is a great community here, but we do ask that you read and try to understand the information being taught. Questions are always welcome and folks will try to direct you and teach you the methods. Start with these articles:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

Just a funny note. You mention high CC. cfherrman pointed out to just remove your cover during the day. I bet while the pool store was selling you shock to "fix" the CC that they never told you that your cover holds CC in the pool and just removing it on a few sunny days would allow the suns UV rays to burn the CC off naturally, did they?

So again, welcome to TFP!!