How To Fix A Cloudy Pool

Causes and cures for cloudy swimming pool water.
Milky pool water, white, pink, brown, purple, black cloudy water.
Swim University

How To Fix A Cloudy Pool

Postby Swim University » Thu 22 May, 2008 09:49

Sometimes when you have a cloudy pool it can be very difficult and time consuming to get it clear. Or sometimes it happens over night. Here Are some tips & tricks to help you clear that pool quickly.

1. Its always good to use some sort of clarifier. What they do is gather tiny particles that are making your water cloudy and bring them together to create bigger particles so that your filter will have a better chance of picking it up.

2. A chemical called Floc or Flocculant is sometimes a good idea if you are in a rush. Lets say you have a pool party tomorrow and your pool is cloudy. But this method is very time consuming and difficult. The idea here is the Floc gathers all the particles that are making your water cloudy and sends them to the bottom of your pool creating a huge cloud. At this point you will need to manually vacuum up that cloud through your filter waste option or backwash port. Again it is difficult and a lot of water is wasted but it will clear your pool in one day.

3. To help your filter pick up more debris, especially if you have an above-ground pool, you can create a bottom-drain effect like an in-ground pool by simply hooking up your manual vacuum and turning it upside down in the middle of your pool. That method will help collect the cloudy particles at the bottom of your pool rather than just your filter skimming the top.


chem geek
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Postby chem geek » Thu 22 May, 2008 10:21

The number one reason for a cloudy pool is algae growth and if you don't kill it with shock levels of chlorine then it will continue to grow and turn the pool green. A clarifier is only useful for clearing a pool of suspended particles such as dead algae AFTER it is killed, but it will not kill algae that is growing. The shock level of Free Chlorine (FC) that is needed to kill algae relatively quickly is 40% of the Cyanuric Acid (CYA) level. If the CYA level is very high (> 80 ppm) then it is usually better to do a partial drain/refill to lower it as it will take extraordinary amounts of chlorine to kill the algae otherwise.

A copper algaecide will kill algae, but has side effects of staining if the pH goes up. A phosphate remover will remove a primary nutrient for algae growth, but is expensive. An algaecide such as PolyQuat 60 is better at preventing algae than killing an existing bloom, but chlorine alone can keep away algae if the FC is never below the minimum of 7.5% of the CYA level. A pool can be cleared of algae using chlorine alone as shown here.

See this link for clearing a pool of algae and this includes a pool that is in the early stages of algae growth and is just dull or cloudy. 100 reasons for a cloudy pool are listed here.

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