Wednesday, October 23, 2013

How Much Clorox Is Needed to Disinfect My Pipes?


How much Clorox per gallon of water is needed to disinfect house piping?  

Susan G.

Hi Susan,

The exact amount of chlorine bleach needed to disinfect your pipes depends on the size of your house and plumbing/treatment systems. As noted on our website, proper and effective shock-chlorination requires:

1. A dosage of 50 to 200 ppm of free chlorine evenly distributed through out the piping and fixtures 
2. Testing of the residual to verify that the levels are present at the fixtures and hose bib or valves sections 
3. Contact time with the piping, undisturbed for 12 hours
4. Retesting of the chlorine residual after 12 hours
5. If the chlorine residual is less than 10 ppm after 12 hours, repeat this procedure from step 1

There are a couple ways to get chlorine into your system, though we would recommend a metering pump for maximum precision and ease of use.  If you have a metering pump, consult the guide at the bottom of this page for best results.

45MHP10 Stenner w/ 15 gal tank 220V
Stenner 45MHP-10
Metering Pump and Solution Tank

If not, you can use the "slug-in" method, though you should keep in mind that this method is generally unreliable and inconsistent, as it relies on introducing a "slug" (large amount of chlorine) into one section of your pipeline and hoping that this dose will properly sanitize pipes downstream.  This method might result in inconsistent chlorine levels throughout your system, or in chlorine levels so high that pipes and appliances may begin to corrode.

However, if you don't have a chlorinator system the slug-in method is the cheapest and easiest way to clean your pipes.  If you are using a whole house cartridge filter, a popular choice, you can dump about 1-2 cups of chlorine bleach into the cartridge and run taps throughout your house until you smell chlorine.  Let the chlorine sit for about 6 hours, then flush it from your system by running the taps throughout your house for a few minutes, until you no longer smell chlorine.

We hope this helps you get those pipes good and clean.  If you have any further questions or comments, please e-mail us at, or leave us a comment/message on Facebook.  Thanks for the e-mail!