How To Shock A Saltwater Pool In 4 Algae Killing Steps


Shocking the pool will typically require you to add large amounts of chlorine in order to raise the chlorine levels to at least 5 or more ppm. This will allow you to kill microorganism and remove large amounts of contaminants in the water. More importantly, it can help you kill algae thriving in the pool.

But you need to keep in mind that when dealing with a salt water pool, salt is used instead of chlorine for sanitation purposes. The swimming pool also needs to have a chlorine generator so that the owner can convert salt into hypochlorous acid and sanitize the pool in the same way that ordinary chlorine does.

However, when it comes to shocking a salt water pool to remove heavy contamination or the heavy growth of algae, you will have to make use of the similar steps to shocking an ordinary pool. Although you can use the generator’s shock setting, I discourage it since it can lower the lifespan of your salt cell.

Preparing The Things That You Need

1. A Chlorine Testing Kit

testing kit

This will help you know whether your combined chlorine is greater than the free chlorine in the pool. It will help you know what the current chlorine level is and if you have successfully shocked the pool.

I highly recommend that you use a good testing kit that is drop-based. Even though they are a bit pricier, they can actually help you get reliable results. If you do not have any, you can opt to use strip tests or hire a handyman to help you test the pool’s chlorine levels.

2. A Pool Brush

pool brush

You will need to use this to remove algae that can be found on the walls or in between the tiles of your swimming pool. If you do not have this, you can use any other type of brush for as long as it will not be too abrasive and will not remove the plaster.

3. A Pool Shock

clorox bleach

You need to use a good shock product if you want to effectively remove contaminants and algae on your pool. You can actually use a non-chlorine shock but they might not be effective against bacteria. If you do not have a pool shock product, you can buy several bags of ordinary chlorine instead. You can also opt to use bleach or liquid chlorine.

4. A Pool Vacuum

pool vacuum

You will need to use this to remove the dead algae. If you do not have one, you can use the pool filter and let it run for at least 24 hours. Keep in mind that this might strain the filter. You should also consider cleaning the filter after using it to remove algae.

How To Shock A Saltwater Pool

Step 1: Check The Pool

chlorine testing

You need to assess the problem first by taking a look at how severe the contamination is. You should try to test the chlorine levels of the pool using a testing kit so you will see what its current level is. If there is an algae bloom in the pool, you will have to use a pool brush to remove them from the pool surfaces.

Doing so can make the shock more effective and it can help you to get rid of the algae effectively. While you are at it, try to see what type of algae is thriving in the pool. You can also test if the pool’s pH or iron is high. Chlorine cannot react properly to high alkalinity and it can cause staining with high iron content.

Step 2: Calculate How Much Chlorine Shock You Need

chemical by the pool

Although a chlorine level of 5 ppm is good enough for getting rid of chloramates and minor contamination, if you want to completely get rid of the contaminants and the algae in the pool, you will need to raise the chlorine level to as much as 30 ppm. This is called breakpoint or complete chlorination.

Use 3 pounds per 10,000 gallons of water if you are using dry chlorine shock products. If you are using bleach or liquid chlorine, you will have to use as much as 5 gallons per 10,000 gallons of water. These measurements will help you achieve a complete pool shock.

However, if the pool has dark green algae, you might have to increase the amount of chlorine shock you are using. You can also quadruple the amount of shock you need to use if you have black algae or if you have been neglecting the pool for several months.

Step 3: Applying The Shock

ripped pool water

Turn the pool filter on and put the chlorine into the pool. You can do this by spreading it all over the surface or adding from the edges. If you have a vinyl pool, a fiberglass pool or a painted pool, you will have to dissolve the chlorine in a large bucket of water first before trying to add it into the pool.

You need to be very careful not to let clumps or granules of chlorine touch the bottom of the pool so that you can avoid damaging these types of swimming pools. You can also opt to use liquid chlorine, or pool shock products that will dissolve upon contact.

Step 4: Vacuuming And Waiting For The Pool To Normalize

pool vacuuming

After applying shock, you will have to wait for a couple of days since the pool will still have very high chlorine levels for quite some time. You can check the chlorine levels by morning so you can see the actual levels. If the levels of free chlorine have gone down, you will have to do the shock again.

After a successful shock, the pool water should no longer be green. Instead, it should be cloudy blue. If you can see this by morning, you can proceed to the cleanup by vacuuming the pool and letting the filter continue to run. Re-test the chlorine levels first before you try to use the pool again.


Shocking a saltwater pool is similar to shocking an ordinary swimming pool. Although you can opt to use its shock setting on the chlorine generator, it will typically not be able to produce enough chlorine to reach the breakpoint chlorination.

Shocking the pool requires the use of calculated and precise methods so that you will be able to get good results. Although it can be quite tedious and time-consuming, if you do it properly, you will be able to get a pool that is contaminant and algae-free.

About the Author Emily Taylor

My name is Emily Taylor, gardening is my passion and I’m looking forward to sharing it with everyone. I know that there are millions of people out there want their backyard and garden be attractive just like their front yard, so I am here to help you create your own backyard paradise.

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