Should I backwash after shocking the pool?

Author: Rosa Kunde IV  |  Last update: Friday, September 12, 2025

If you're dealing with an algae infestation, brush the pool after shocking to remove lingering debris and run the filter. Rinse or backwash your filter to avoid recontamination. If you've still got traces of algae, shock your pool again. After shocking, test your water chemistry.

Do I need to backwash after shocking the pool?

Yes you can backwash the morning after shocking. My rule of thumb is back wash until clean, rinse 10 seconds, backwash again, rinse 10 seconds, Obviously turning off the system between each step. Set filter to Filter and open pressure valve.

When should you not backwash a pool?

You only need to backwash the filter when it reads 10psi above the normal operating pressure. So let's say you backwash or do a full clean, and right after the backwash or full clean the pressure gauge reads 12psi, then you backwash when the pressure gauge hits 22psi. Otherwise you're just wasting water and DE.

How long should I run my pool filter after shocking?

Would recommend a minimum of 5 hours with the filter running. 8 hours preferred (apply at dusk and let it work overnight). this specific product is likely to cloud the water at first, and then the sediment will fall to the bottom of the pool and require vacuuming. that's normal for these types of products, don't worry.

Should I brush pool after shocking?

wait till you can do it all at same time. Do wait 30 minutes between shock and algaecide but you will be brushing for that long.

How Often Should You BACKWASH A POOL FILTER?

What to do after you shock your pool?

After shocking, test your water chemistry. Make sure all the levels – chlorine, pH, alkalinity, calcium hardness and CYA – are within the correct range. Adjust if necessary. If chlorine levels are too high, let the sun evaporate it.

How long does it take for shock to clear a pool?

Don't worry, your treatment has not gone into waste. Even if you shock your pool properly, it takes a while for the natural microorganisms to do their job. This can take up to 12-24 hours, as opposed to a couple of days with harsh chemicals. Thus, the pool water takes time to get clear.

Should I vacuum my pool after I shock it?

Vacuuming After Shocking

As mentioned, you should vacuum your swimming pool as much as possible to keep the job manageable. However, after shocking the pool, you shouldn't vacuum for at least 24 hours. Running the water pump during this period will allow the shock to do its job.

What happens if you put too much shock in the pool?

Is it possible to shock your pool too much? Yes—excessive shocking of your pool will keep it at an elevated chlorine level. This will cause irritation of the skin and eyes as well as excessive wear and tear on your pool filter system, including excessive corrosion of all metal parts.

Is it better to run pool pump at night or day?

Running the pump during the hottest parts of the day helps to combat the effects of the sun, especially with deterring algae growth and removing bacteria and debris during peak swim times. Splitting up time into shorter intervals and running during the morning as well as in the evening may help to maximize efficiency.

Why is backwash bad?

Backwash is the term used for fluid which makes its way from a person's mouth back into a drinking container. Why is backwash considered bad? If you're sick, you could be putting sickness causing bacteria back into the container and if someone else drinks from it, they could get sick too.

How often should I shock my pool?

Shocking your pool regularly will help to keep the water clean and free of contaminants. You should aim to shock your pool about once a week, with the additional shock after heavy use. Some tell-tale signs that your pool needs to be shocked are cloudy, foamy, green, or odourous water.

Does backwashing drain your pool?

Backwashing can result in a loss of water. While this is unavoidable, you can minimize the amount of water you lose by not overdoing the backwashing process. Keep a close eye on the colour of the water through the view glass and stop the minute it becomes clear.

Can you backwash a pool too much?

Avoid Backwashing Too Frequently:

Backwashing too often can reduce the filter's effectiveness. The sediment layer helps improve filtration by trapping finer particles. If you backwash before it's needed, you lose this beneficial layer, which can result in cloudy water.

Is shock the same as chlorine?

1) What is the difference between chlorine and shock? Do I need to use both? Chlorine is a sanitizer, and (unless you use Baquacil products) is necessary for maintaining a clear and healthy pool. Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly.

Why does my pool look worse after shock?

Pools can immediately turn green after being shocked when they have metals like copper in the water. These metals oxidise when exposed to high levels of chlorine, which makes the pool water turn green. Adding a metal control product such as Zodiac Metal Remover will help to restore the pool water.

Does shocking a pool raise pH?

Calcium Hypochlorite: Also common known as “cal hypo,” this shock is the most powerful and fastest acting shock available. Both an oxidizer and sanitizer, cal hypo is quick dissolving and is the most frequently used in the pool industry. It will slightly raise your pH, so make sure you adjust pH while using it.

Do you add algaecide or shock first?

Algaecides act as a backup to your normal sanitization program and prevent algae from starting and growing in the pool. Algaecide should be added after every shock treatment.

How long after shocking a pool does it clear?

It's not too uncommon for your pool water to be slightly cloudy after shocking, especially if you use a granular chlorine shock. It typically takes about 24 hours for the granules to fully incorporate into the water and disappear. Most cloudy water issues after shocking should resolve within an hour or two.

Do I leave my pool pump on when I shock it?

To ensure chemicals are dispersed evenly in the pool, most suppliers recommend you run your pool pump while adding chemicals to the water.

What neutralizes pool shock?

Add sodium thiosulfate

Sodium thiosulfate is another chlorine-neutralizing compound. It works similarly to hydrogen peroxide by reacting with the chlorine from the water. The quantity you'll need will depend on the size of the pool and the current chlorine levels.

How many times should you shock your pool?

It's recommended that you should do a pool shock once a week. The more you use the pool, the more often you need to shock it. Occasionally, you may need to perform an extra pool shock after: Heavy pool use, like a pool party.

How to get crystal clear water in a pool?

Step-by-Step Guide to Crystal Clear Pool Water
  1. Step 1: Balance the Water – pH Regulation1. The pH level of your pool water is crucial for both the comfort of swimmers and the effectiveness of the chemicals used. ...
  2. Step 2: Disinfect the Water. ...
  3. Step 3: Algae and Bacteria Prevention. ...
  4. Step 4: Flocculation. ...
  5. Step 5: Filtration.

Why did my pool turn green after I shocked it?

Culprit 2: Copper-Based Algaecides

While copper-based algaecides are very useful for ensuring that algae growth is prevented, using too much can actually spike up the copper levels in your pool to make it reactive enough to your chlorine to turn your pool water green!

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