How Long To Run Pump After Shocking?

How Long Should I Run My Pool Pump After Shocking?

Shocking your pool is an important part of maintenance that eliminates pollutants as well as active contaminants like algae and bacteria.

It is important to keep these products well-circulated in your water as they perform sanitation, leaving many pool owners wondering: how long should I run my pool pump after shocking?

In this article we will talk about how long you should run your filter after shocking your pool and what can happen if you don’t run your pump for long enough.

How Long To Run Pool Pump After Adding Chlorine Shock

Regular Maintenance

If you are adding a maintenance shock treatment to your pool, it is essential to run your pump and filter for a minimum of eight hours afterwards.

This gives the shock treatment time to adequately circulate throughout all areas of your pool’s water and equipment, while also allowing time for your filter to remove any contaminants that may build up during the sanitation process.

It is important to note that this amount of time does not vary much between types of shock treatment.

Whether the shock product that you choose to use contains chlorine or is a chlorine-free formula, similar waiting times should be observed unless otherwise indicated on the product’s packaging.

Treating A Problem With Shock

If you are adding more shock product to your pool than is required for a regular maintenance dose, such as when you are treating an active algae infestation or other bacterial issue, you should run your pump and filter for much longer after dosing your pool.

In pools with higher levels of water contamination, more circulation is required to achieve similar levels of sanitation during a shock treatment. In these cases, it is advised that you let your pump and filter operate consistently for a 24 hour period following the use of a shock treatment.

In addition to allowing the sanitation elements to circulate properly, this extended filter time works to remove any dying algae and related debris that can otherwise conceal more active contaminants.

Why Running Your Pump After Adding Shock Is Important

As mentioned above, running your pump after adding a shock treatment is essential for keeping the sanitising agents well-circulated in your water.

This allows the shock treatment to come into contact with as much algae, bacteria and other organic material as possible, achieving a more thorough sanitising effect.

If you do not run your pump after adding a shock treatment, the shock treatment will not affect the entire pool.

Sanitation may only occur in this isolated area, near where the shock treatment was introduced to the water. Without proper water circulation, this product cannot perform its function and clean your pool as it is intended.

If the pump is run for only a short period, there will be dead zones of poor mixing in your pool (typically the corners) where the free chlorine concentration will remain low and microorganisms can thrive.


You should always run your pool’s pump after adding a shock treatment. Although a minimum waiting period of 8 hours is advisable, in some cases it is more appropriate and even more beneficial to allow your pump to run consistently for a 24 hour period following the shock.

Note that these recommendations assume that your pump is appropriately sized and meets recommended turnover times. If this isn't the case, you'll need to run it longer.

Do you have any questions about how long to run your pump after adding shock? Get in touch with us in the comment section, we’d love to help!

Louis from Pool Advisor


A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.