How to Fix A Cloudy Swimming Pool

Cloudy swimming pools are the stock and trade of any swimming pool service contractor. While it makes us money a cloudy pool is annoying as a homeowner. Especially when you are dealing with a perpetual problem of cloudy swimming pool water. Here I want to address this headache of pool water chemistry and help you get to the bottom of it (figuratively of course) and troubleshoot and diagnose the cause of cloudy water in your own swimming pool.

One thing to realize about cloudy swimming pool water is that no one wants to swim in it. It can be downright dangerous to do so. Depending on the reason for the cloudy water, there can be unwanted ‘things’ in the water swimming with you that could make you very sick. It could also be reflecting issues with the equipment keeping your pool water clean. Also, when a pool is cloudy to the point that the bottom drain can’t be seen from on the deck, someone could drown without bystanders realizing it. No one should ever enter or swim in a pool that is cloudy.

Let’s explore some of the possible causes of cloudy swimming pool water, and the fixes that go along with them.

What Causes Rapid Pool Water Cloudiness?

In general, a pool won’t turn cloudy extremely quickly, unless there are some extreme circumstances causing it. It’s a bit more noticeable if your pool is typically crystal clear and you come out and suddenly notice the water is less sparkly (yes sparkly is a word) than usual. Quit often a huge spike in bather load will make a noticeable difference like this. (maybe a pool party).

I’m going to assume that as a pool owner, you will know chemistry basics, like pH, chlorine, and total alkalinity. If you don’t, check out this post first and then comeback.

Organic Debris Causes Sanitizer Demand

Organic debris that drops into your swimming pool puts an inordinate load on the demand for sanitation. While the sanitizer (chlorine) can handle almost anything if the levels are maintained, heavy loads of leaves, grass, or other yard materials can put an extreme strain on the sanitizer’s ability to keep up. It’s best if there’s a large amount of debris, it is removed as soon as possible. The pool’s filtration will remove this from the surface of the pool. But if not removed from the filtration, the debris will still breakdown inside the filter and cause issues.

Bathers…. including people, fur-babies, or otherwise will add to this demand for sanitizer. Yeah, yeah, I know…everyone that gets into your pool takes a shower first, and your dog is cleaner than my kids (probably true).

We all introduce contaminants that require sanitizer, no matter how squeaky clean we think we might be. Humans sweat, urinate, use sunscreen, lotions, and oils. Dogs, well, are dogs. Anything ‘foreign’, which includes bathers, will use up sanitizer.

So again, if you have a huge bather load as in the case of a pool party, your existing chlorine could get used up quickly. Thus, leaving behind large amounts of pollutants that can’t be sanitized. In turn, creating a cloudy environment.

Swimming Pool Filters Job

In my 15 or so years on the job, I can say without reservation that the filter, or more accurately the circulatory system is the primary cause of swimming pool water becoming cloudy. I’ve covered this in other posts and even my first ever YouTube video is of me showing how to properly maintain a swimming pool filter.

Under perfect conditions where the system was designed correctly, the flow rates are right, the pump is running at full efficiency for the right length of time, and the filter is clean it is highly doubtful that you will have a cloudy pool. And if you do have a cloudy pool, this won’t be the cause.

So those are big “IF’s”! In my experience, many pool’s plumbing systems were poorly designed or were designed when we had a different understanding of pool plumbing and hydraulics. Many pumps are getting old and are under-maintained, or otherwise lack peak efficiency. And Filters quite often go WAY too long in-between cleanings. I once had a new customer tell me they never had cleaned their filter…it was over 7 years old!!

How to Clear Up Cloudy Swimming Pool Water

Now that we got the diagnostic / troubleshooting part out of the way, let’s do a step by step on how to get a pool cleared up. These steps may need to be repeated and done out of order depending on the causes of the pool being cloudy.

Pool Filters Clear Up Cloudy Pool Water

You’ll want to service your filter. There really is no way around it. A funky Filter will cause a cloudy pool, or at the very least contribute to it. No matter how long you run the pump, no matter how much chlorine or other chemicals you add. If your pool’s filter is packed or damaged, the pool will never clear up.

Step one:  in fixing a cloudy pool is to backwash your pool filter, in the case of D.E. or Sand Filters. If you have a Cartridge filter, open it up and give the cartridges a good solid cleaning. Even if you have Sand or D.E., though time-consuming, it’s never a terrible idea to open the filter and give everything a good once over. Even if the filter is fine, you can eliminate it as the cause of the cloudiness.

When I’m dealing with a cloudy pool, I always check for small cracks in the internal parts. I’ve seen it happen several times over the years. A crack in the internal manifolds that is barely visible. Check the breather tube too. There should be a small finger screen or cheesecloth mounted to the top of it to prevent tiny debris from working it’s way back to the return lines.

Pool Shock To Clear Cloudy Pool Water

Step two: Quite often the chlorine is locked up with ammonia or other compounds and it creates ‘chlorine lock’, or chloramines. To snap out of chlorine lock, you need to shock the pool with a high-quality non-chlorine shock. You can also ‘super-chlorinate’ to produce the same effect.

It’s important to note, that you need to keep the pump running during this process. In addition, filtering or cleaning the water, the water needs to be circulated to provide equal coverage of the chemicals. Which leads me to the next step.

Pool Maintenance Will Clear up Cloudy Pool Water

There are regular maintenance items that you should be doing already that you will need to increase to clear things up. Brushing. Netting. Vacuuming.

Step three: Brush down the pool as often as you can muster, 1-2 times daily is best. Focus on areas where the water doesn’t circulate well, steps, ladders, swim-ups. Not only does it help bacteria and algae and other things not take hold, but it also moves the water around.

Net out anything that falls into the pool. Any leaf, any shred of grass. Become a pool netting ninja. Run the vacuum as debris falls to the bottom. If the debris at the bottom is enough, you will need to service the filter…see step one (again).

Check out my Ultimate Swimming Pool Maintenance Checklist

Chemicals That Help Clear Up Cloudy Pool Water

Step four: You should spend as much time as is needed on the first three steps, don’t try to rush the steps. As things start to clear up, you can start getting the water safe for bathers again. Bring everything into balance, pH alkalinity, and of course chlorine. There are other parameters that you can look at, but we want to stick to just the necessities for this step. If you want to know about more chemical balancing tips, checkout this post on pool chemistry.

Pool Water Clarifiers and Other Supplements

Step Five: This is really an optional step, as I have gotten a cloudy pool back to sparkly several times without pool supplements. If you have access to a good quality pool supplier, I recommend using a high-quality pool enzyme. Try not to waste enzymes by using them right before you clean the filter. Enzymes help clear up pool water by essentially ‘eating’ organic matter and oils that are suspended in the pool water.

Clarifiers are another great option for capturing the tiny stuff that is clouding up your pool. To explain this in a very elementary fashion, basically clarifiers force the tiny stuff together that the filter can’t capture into making larger globs that the filter can actually catch. I like to use just a touch of clarifier every other week as a regular routine.

If you are just having a rough time getting the pool clear, you can use a flocculant. Similar to the clarifier, floc will bond smaller stuff together. Instead of going to the filter, they will drop to the floor of the pool since most require the pump to be shut off for about 24 hours. You need to vacuum after and hopefully, you can vac-to-waste, so you don’t have to service the filter after it’s done its job.

A Clear Swimming Pool Is A Happy Swimming Pool

Hopefully you’ve seen the overall theme of this is that if your pool equipment, chemicals, and maintenance is going right, there should never be any cloudiness to worry about. If a once sparkly pool is starting to cloud up, don’t let it slide, check things out immediately to get ahead of it.

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