Say Goodbye to Cloudy Water: Proven Pool Treatment Tips

You’ve slipped into your cozzie and raced down to the pool, eager to dive into its cool depths. But as you’re poised at the edge, you notice something unusual. The water’s hazy, even a little opaque. At first, you think it’s a smudge on your swimming goggles or the sunlight playing tricks on your eyes. Then you realise you’ve got a problem every pool owner dreads – cloudy pool water.

But don’t hang up your towel just yet! There are steps you can take to solve this problem, and it doesn’t involve draining your pool. In this guide, we reveal three common causes of cloudy pool water, what you can do to fix it and how to prevent it from happening again. Ready to turn your pool water from cloudy to clear? Then let’s dive in!

Why is your pool water cloudy?

It’s not uncommon to get cloudy pool water at least once every swimming season. The problem can occur gradually after a pool party or quickly after heavy rain. And while cloudiness can vary from dull and hazy to milky and opaque, one thing is certain – something is off with your pool. So what’s going on?

In short, you’ve got too many particles in your pool. This can result from dust, pollen, soil, sunscreen or algae spores. Moreover, these particles carry a negative electrical charge, meaning they remain suspended in your water instead of sinking to the bottom. As a result, they reflect light and give your pool that cloudy look. There are three main reasons why this may happen:

1. Filtration issues

As avid swimmers, we all know that a crystal-clear pool is a must for an enjoyable swim. But what happens when your pool starts to resemble a murky swamp? The culprit is often a neglected and overworked pool filter. Yes, that unassuming equipment tucked away in the pool corner works tirelessly to keep your pool water pristine.

Imagine your filter as a superhero who has lost its superpowers. It needs to perform its duty, leaving your pool water lacklustre and dull. And it does not just neglect that can hinder its performance. If you don't run your filtration system for enough hours each day, your filter can't work its magic effectively. As a rule of thumb, your pump should run for at least 8 hours a day to keep your filter in top shape.

2. Chemical imbalance

Sure, having enough free chlorine is crucial for keeping bacteria and algae at bay. Without it, your pool can quickly turn into a murky mess, resembling more of a swamp than a serene oasis. But there are other hurdles to watch out for. You see, a whole symphony of chemical imbalances can throw your pool off its harmonious rhythm.
Take alkalinity, pH, and calcium hardness, for example. These may sound like technical terms, but they can impact your pool's performance. If your pH is soaring above 7.8 or your alkalinity is skyrocketing over 200 ppm, your free chlorine can lose its mojo, leaving your water cloudy.

And let's not forget about calcium hardness. If it's off the charts at over 400 ppm, it can wreak havoc on your pool's filters and cause unsightly scaling.

So, what's a savvy pool owner to do? Keeping a close eye on these chemical levels and maintaining the perfect balance is key. Regular testing and adjustments are necessary to ensure your pool stays in harmony, providing a new swimming experience for you and your guests.

3. Environmental factors

Imagine this: you've got regular bathers enjoying a swim in your pool, but little do you know, their hair products, body oils, sunscreen, make-up, and yes, even urine, are making their way into your pool water. Not to mention the pesky leaves, dust, pollen, and bird droppings that seem to find their way into the pool as well. And let's not forget about rainfall, especially those heavy downpours that dilute the chlorine and introduce nitrates and phosphates into the water, making it even cloudier.

How to fix cloudy pool water

Fixing cloudy pool water can be tricky, particularly if you’re a newbie pool owner. But if you follow our four simple steps, you’ll be able to identify the root cause and get your pool back on track again.

Step 1. Check your filter

Take a look at your filter and see if it needs cleaning, service or replacement. If you have a cartridge filter, check the pressure gauge, then take it out and give it a good hose down. For a thorough clean, soak the cartridge in a tub of clean water with some filter cleaner for at least 12 hours. After that, give it a good rinse, and it should be as good as new! In general, cartridge filters should be replaced every two years, so keep this in your pool diary! Remember, for an average-size pool, you should run your filter for 6-8 hours per day in the summer and 4 hours per day during winter.

For those who have a media filter - If it has been a few weeks or even months between backwashes, the sand filter could be due for a good backwash. The general rule of thumb is to backwash fortnightly or monthly. Chances are, you will notice that the water that comes out of your filter during the backwash is very brown and dirty. Let the backwash run for a minimum of 2 minutes or until the water turns clear on your sight glass. Sand media lasts for anywhere between 5 to 7 years. If you are backwashing your filter and still noticing dirty water coming out after 2 to 3 minutes or no clarity in your water following a chemical treatment or backwashing a few times, this means it is time to change the sand or media.

Step 2. Check the pump

If your filters are in good shape, then there might be a problem with the pump. If it’s too small for your pool, it won’t be able to filter enough water regularly. The same applies if it’s too old. If you’ve had your pump for more than 10 years, it may struggle to circulate and filter your water properly. Consider getting it serviced or buying a new one. If you don’t know how old your pump is, look up the serial number or speak to a pool professional for advice.

On the other hand, if your pump is new, you may not be running it often enough. When your pool has more traffic than a Boxing Day sale in summer, your pump should run for at least 8–10 hours a day. Depending on the size of your pool, this should clear up the cloudiness in a couple of days.

Step 3. Balance your chemicals

You should be checking your pool chemistry every week, but if you’ve been negligent or life has gotten in the way, it could be the reason why your pool is looking murky. Here are some common imbalances and how to fix them:

Low sanitiser levels

Ideally, your chlorine level should be 2–3 ppm. If it’s too low, it can lead to bacteria or algal growth – a common cause of cloudiness. To fix this, add chlorine tablets or liquid chlorine. To protect chlorine levels in the future, consider buying stabilised chlorine or adding cyanuric acid (CYA). This slows down the breakdown of chlorine by UV rays and allows the chlorine to last longer in your pool.

If you don’t want to waste time taking water samples, try shocking the pool. This is great for raising chlorine levels quickly (also known as superchlorination). Preferably, do this at night so the sunlight can’t dissipate the chlorine as quickly.

High pH, alkalinity and calcium hardness

Follow our instructions in How to Test and Fix Your Pool Water to test the chemical levels of your pool. If the pH of your pool water is high, the efficacy (or killing power) of your pool chlorine is greatly reduced, which may cause the water to appear cloudy. From the graph shown below, you can see that pH is an important factor in making sure the free chlorine is an effective disinfectant. To fix high pH, dose your pool with pH Down or Liquid Pool Acid so that you reach an ideal pH level of 7.2-7.6.

Source: Pool Water Treatment Advisory Group

High calcium hardness levels also lead to cloudy pool water and calcification. It can be corrected with a hardness reducer, such as Calcium Down or fresh water from your garden hose. If you have a concrete/tiled pool, you should aim for 200 – 400ppm (Ideal 300); if you have a vinyl or fibreglass pool, you should aim for 100-250ppm.  

A high TA (Total Alkalinity) causes pH and calcium scaling, both of which are associated with water cloudiness. To fix it, you can add pH Down or Liquid Pool Acid to the deepest end of the pool with the pump off for 2 hours before turning it back on until you reach an ideal range of 100-200ppm.

Step 4. Remove environmental debris

You should start with removing any leaves, twigs, or other debris in your skimmer or pump basket. Emptying the baskets will allow for proper water flow and circulation.

Next, you should remove visible leaves and dirt by using a skimmer, brushing the walls and vacuuming manually. To help things along, use a pool brush to stir the water and allow the particles to come to the surface.

If you’ve got tiny particles that can’t be removed by your skimmer or filter, use a pool clarifier. It’s available in liquid or tablet form and helps particles clump together so your filter can remove them effectively. It may take a couple of days for the debris to disappear completely, so make sure your pump runs for at least 24 hours for the best results.

If you have very cloudy water, use a pool flocculant. Both clarifiers and flocculants bind microparticles into larger particles. However, the particles created by clarifiers are removed by the filtration system, whereas flocculants require extra time and effort to manually vacuum particles that have dropped to the pool floor.

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

It all depends on the cause and severity of the cloudiness. In general, it can take up to three days for chemicals to balance, or less if you use a pool clarifier. Keep testing, run the pump and adjust the chemical balance until your water is crystal clear again.

Pro tip: If you have shocked your pool, it’s not unusual to get some temporary cloudiness. This should resolve when you run the filter for a few hours.

Is it safe to swim in cloudy pool water?

When you don’t know the root cause of the cloudiness, it’s best to play it safe and stay out of the pool. There are a couple of reasons for this. First, swimming in cloudy water doesn’t allow you to see the bottom, making diving and swimming unsafe. Second, there could be algal growth or bacteria (like E. Coli) that can cause stomach problems, urinary infections, red eyes and skin irritation. As a result, stay out of the pool until you’ve eliminated the problem and balanced the pool water.

How can you prevent cloudy pool water?

Prevention is better – and faster – than cure. First, make sure you buy high-quality products for your pool. Don’t skimp on pumps, filters or chemicals. Choose reputable brands that are suited to your pool size and type.

Second, use a cover when your pool is not in use. This will reduce debris and water evaporation, which can contribute to imbalances and cloudiness. If you can’t do this, consider trimming trees or shrubs that may be dropping pollen, leaves and seeds into your pool.

Lastly, keep up a weekly maintenance routine. This includes cleaning, testing the water, checking the pump and filter, skimming, vacuuming and shocking your pool. And don’t wait too long if you see chlorine, pH, or calcium levels creep up or down. Fix them straight away, or you might wind up with stubborn issues further down the track.

Wrap up

Nobody likes to wake up to a cloudy swimming pool. But it doesn’t have to spell the end of your pool party or swimming season. Whether it’s a clogged filter, low chlorine levels or tree pollen, you can get your pool back on track by following these four simple steps:

•         Backwash or replace your pool filter
•         Run your pump for at least eight hours a day
•         Balance your chemical levels 
•         Remove debris

If you’re in a rush or can’t identify the cause, give your pool a shock or use a clarifier to remove stubborn particles. Once the cloudiness is gone, keep it clean by sticking to a weekly pool maintenance schedule. Not only will it save you time and money, but it’ll keep your pool swim-ready all year round. For more information on keeping your pool in tip-top condition, dive into our Pool & Spa Guides. If you’re after products or services, get in touch with one of our approved dealers.