How To Go From Cloudy To A Crystal Clear Pool


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A cloudy pool is a very common occurrence for swimming pool owners. The most common reasons for a cloudy pool are a chemical imbalance, improper pump and filter size and algae.


Step by Step


Step 1

Chemicals- The first thing you will want to do is test your chemical levels. You want to be consistent with your pool chemical levels. Test often to ensure you have the proper amounts of chlorine and other chemical levels in your swimming pool. Use our Aqua Check 6-Way Test Strips to check for the following proper levels. If any of the levels are not within range, they will need to be adjusted.

Step 2

Filter - Make sure that your pool filter is working properly and is clean or backwashed. Also ensure that your pool filter valves are properly installed and working. Make sure that the filter valve is also in the correct position. Sand and d.e. filters require backwashing (whenever the pressure reads 8-10 psi above normal). They also require a certain amount of sand/d.e. The filter label should indicate the proper amount to be added. For a cartridge filter, clean your cartridge regularly and inspect it to make sure it is still filtering properly. Depending on the use of your swimming pool, Inyo recommends that you replace your pool filter cartridge once per season.


Step 3

Pump maintenance- Your swimming pool pump is the driving force of your filter system. The average amount of time a pump should be run per day is 8 hours. If you are getting cloudy pool water, you may want to try running it for a longer period of time. Also make sure your swimming pool pump is properly sized for your filter. If you have a higher GPM rating on your pump than your filter, it is too much for your filter to handle. This will lead to the water being passed too quickly through the filter causing poor filtration. 


Step 4

Too many people in the pool- If your pool is getting a lot of use with a lot of people this create added stress to your pump and filter. Oils, urine, and other organic waste from a bather load needs to be cleaned. If this is the case run your pump for a longer period, shock it with a non-chlorine shock (if the chlorine levels are o.k.) and add a clarifier.

Step 5

Algae Growth - Whether it is dead or alive, algae will need to be removed from your swimming pool. Depending on the amount of algae in your pool there are a few steps. If your pool is very cloudy and turning green, please follow the following steps.



(1 to 20 of 20)

 Posted: 4/8/2020 

I added too much soda ash, too soon after supershock and algaecide. In about 30 minutes, pool water turned white milky cloudy. Backwashed filter, and white milky colored water is all that came out. After 24 hours....still the same. I know I did it wrong. How do I un-do it? Cannot take water sample to pool store now or go buy test strips.

InyoPools Product Specialist  Posted: 4/9/2020 

It could be a couple of things. First, the shock maybe has worked and killed all the algae. Dead algae turns white and can give your pool a cloudy look. Secondly, the combinations of algaecide and shock used in concert will turn the pool milky or cloudy. For both of these scenarios, you may use an enzyme cleaner like Pool First Aid or a clarifier to help clear up the color. Shock and algaecide should not be used together; I would just stick with the shock for now.

 Posted: 7/29/2019 

have a Hayward sand filter. I've noticed when vacuuming that the dirt is returning through the return. Your thoughts???

InyoPools Product Specialist  Posted: 7/29/2019 

The most common causes of sand in your pool are a bad spider gasket or cracked laterals. We cover a few other causes in this guide, How To Reduce Sand in Your Pool.

 Posted: 7/24/2019 

How often can I shock my pool? I put in shock and algaecide in my pool.Not sure if I ran filter pump long enough. And it's cloudy. What do I do?

InyoPools Product Specialist  Posted: 7/31/2019 

You can shock the pool as often as needed. If the free chlorine level is low, shock the pool again. A cloudy pool is usually a sign that the algae has been killed. The dead algae needs to be filtered out. A water clarifier will help speed up the process.

 Posted: 6/16/2019 

Hi I’ve shocked the pool, it’s balanced and I’ve tried clarifier. I changed the sand in our filter and it’s still cloudy. The colour is right but it’s not clear unless the filter and pump are off. I went to the pool store the sales man wasn’t sure what to suggest. What should I do?

InyoPools Product Specialist  Posted: 6/17/2019 

When you were shocking your pool, were you adding algaecide as well? Certain types of algaecide have a side effect of causing cloudy water. Eventually the algaecide will get filtered out and the cloudiness dissipates. 

 Posted: 7/13/2018 

Hello Maria - We'd recommend trying a product called Pool First Aid. I've seen it clear up pools where you couldn't see the first step.

 Posted: 7/12/2018 

I've done everything described and nothing is working. I test my water and the chlorine side of the test strip is yellow and ph level is bright red. I'm confused as to what to do next. I need help.

InyoPools Product Specialist  Posted: 8/28/2017 

Anthony S - I assume when you replaced your filter that it is at least as large as your old one. You may be seeing the effects of contaminants that have built up over the summer. Try shocking your pool, brushing the side and cleaning the filter. If you have cloudiness the next day, repeat the process. Don't skip brushing and cleaning. Repeat the next day if required. It is important to get the algae residue off of the walls and out of the filter. I've done this several times over the years and always had success. Make sure your pool chemicals, other than chlorine, are balanced.

 Posted: 8/27/2017 

Qurstion -- I have an inground pool approx 30,000 gal all summerthe water has been perfect ... We recently canged our filter because the other one finally gave out .. Now 2 -3 weeks in I can not get the cloudyness out of my pool what sould I do ?

InyoPools Product Specialist  Posted: 8/25/2017 

kristen - It may be time to really clean your filter. If you have a sand filter, replace the sand. If you have a DE filter, disassemble the grid assembly and clean off each grid. For a cartridge filter, buy a new cartridge or soak the cartridge in a degreaser solution to clean out the oils and chemical that build up in the folds.

 Posted: 8/24/2017 

Water is bright blue, chemical levels are perfect. Water is still cloudy even after using a clarifier. Any suggestions?

InyoPools Product Specialist  Posted: 8/11/2017 

Teresa in MA - The key to clearing algae from your pool is persistence. See our recent blog/video on "How to Clean a Green Pool". It has been proven to work. I've used the procedure twice myself.

 Posted: 8/8/2017 

I have added alkalinity and water hardness, plus 3 bags of shock and still the water went from blue gray and green now. Just 3 wks left of summer and couldn't have a cookout with pool party due to the water not clearing up. My husband really wants to have the pool removed. Not sure why this year is especially harder to get the water clear. Thank you, Teresa - 8/8/17

InyoPools Product Specialist  Posted: 7/20/2017 

Teresa - Check the spider gasket in your Multiport Valve. If it is damaged, it may be letting dirty water back into the pool during backwash and rinse. See our guide on "How to Replace a Spider Gasket on a Multiport Valve".

 Posted: 7/18/2017 

Clean my pool and dirt comes right back. I checked all laterials and none of them were broken nor was the pole. Any ideas?? Also, changed sand

InyoPools Product Specialist  Posted: 4/1/2015 

Janice - You do not have to replace the sand in your filter after an algae outbreak. But depending on the severity of the algae outbreak, you may have to backwash your sand several times as it is filtering the algae and you might have to shock your system several times. As your water turns clear, the same chemicals will clear your filter. Once your water is clear, follow up with an algaecide.

 Posted: 3/31/2015 

Is it necessary to change the sand in your filter after an algae outbreak? I had green algae and I believe there was mustard algae also.