How To Fix Cloudy Pool Water

Oh, no!!  Not cloudy pool water again!!  Is your pool party ruined?  Does your pool look like someone poured 100 gallons of milk into it?  Not only can this ruin your weekend, it's not too good for your pool.  It looks bad and can be harboring nasty bacteria.  Learn how to clear up your cloudy pool water fast and get back to what you do best, swimming!!  A cloudy pool, next to green pool water, is the biggest complaint among pool owners.  Sometimes you'll seem to have milky pool water overnight.  What can you do to get back your crystal clear and clean pool?

Where Does Cloudy Pool Water Come From?

There could be many reasons for cloudy pool water, so check out this list and see if any apply to your swimming pool.  Before you go out and spend hundreds on chemicals that "they" say you need, check this list to see if any apply to your situation.  I know this is a HUGE list, but it's worth the time invested to do a little homework, compared to spending TONS of money at the pool store:  

• Bad or inconsistent chlorination. 
• Excess dead or dying pool algae.
• Pool pump and filters are not running long enough.  It's 4 - 6 hours in the Winter and 10 - 12 hours in the Summer.
• Too much sodium bicarbonate and/or calcium chloride which can produce hard water scale.  
• Wrong/bad level of cyanuric acid (pool stabilizer/conditioner), or Dichlor.  CYA should be 30 - 50 ppm.
• Using or over-use of calcium hypochlorite (granular chlorine).
• Pool chlorine tablets/smart sticks old or ineffective.
• Use and/or over-use of flocculation (flocculate) in swimming pool water.
• Pool pH too high.  The range is 7.2 - 7.8.
• Inground pool covers left on for too long.
• Pool ionizer or pool ozonator not functioning properly.
• Clogged or improperly working pool filter system.
• Bad swimming pool shock (not using enough for your size pool).
• Cracked or leaking pipes from skimmer or pump causing bubbles in the pool.
• Bather load too high for a period of time.
• Use and/or over-use of Baquacil, Proteam Supreme, Softswim, or Bioguard pool chemicals.
• Bad/wrong pool water chemistry and poor weekly pool maintenance.
• Wrong or old pool acid.
• DE pool filter is cracked, not cleaning correctly, or is leaking DE back into the pool.
• Sand in sand filter too old, has low sand, not backwashed fully or correctly, or sand has "channeled" down the side of the filter housing.
• Poorly functioning pool water filters.
• Wrong chemicals for salt water pool systems/saltwater pools, bad or inconsistent salt water pool maintenance.
• Bad, shorted out, or calcified chlorine generator pool/salt cells.
• Multi-port valve damaged, is cracked, damaged gasket, or plumbing is wrong.
• Pump worn out or impeller broken or blocked.
• Pipes are clogged up with a foreign object or gummed up through chemical use.
• Refinished pool plaster.
• Over-brushing of new pool plaster.
• Dust, pollen, or mud.
• Use and/or over-use of phosphate remover such as "Phosfree".
• Over and/or use of wrong pool algaecide.  Only use PolyQuat 60.
• Supersaturation of chemicals not in line with the Langelier index.
• Bad or wrong swimming pool winterization/pool closing.
• Onset of pool algae and/or green pool water.

As you can see from this list, there are many reasons why you can have cloudy pool water.  One of the WORST, and very expensive, pieces of advice you can hear is, "Oh, you have a cloudy pool?  Well, let me tell you how to clear it up.  First is you need to get your pH and alkalinity in line, then shock the pool and add some phosphate remover.  If that doesn't work, add a bottle of algaecide, let it run for 4 hours, and add a couple of tabs in the skimmer.  If that doesn't work, add some Green Out, more phosphate remover and two bottles of clarifier."  

Folks, that advice (if you can call it that) will absolutely cost you hundreds of dollars and TONS of frustration.  That is NOT how to clear up a cloudy or green pool.  However, it is the best way to ruin your Summer and drain your wallet. 

But let's really get down to it and check out 4 main reasons why your pool water is cloudy.

4 Reasons Why Your Pool Water Is Cloudy

We now know the many reasons why pool water can go cloudy.  Cloudiness could be part of a much larger problem.

1. Low Sanitizer Levels

Your chlorine sanitizer plays an important role in keeping your pool water properly sanitized.  It's busy killing all the yuckies in your pool.  Low sanitizer levels can cause algae and bacteria growth and add more stress on your filter.  Pools with lower levels of sanitizer will expose swimmers to dangerous contaminants such as Crypto.

2. Onset Of Algae

When your pool has an onset of algae, it clouds the water and makes it impossible to see through it.  Your sanitizer might not be doing its job of killing the algae.  When the algae is able to thrive, it can double in size in 24 hours.  We can now see how fast a pool can go from clear and perfect to cloudy and/or green.   

3. Filtration Problems

We'll never clear dirty water with a dirty or non-working filter, so let's keep them clean.  Having a clogged filter and not running your filtration system long enough can cause a cloudy pool.  Filtering your pool water 8 - 10 hours per day during the swimming season is optimal.  All that dirt and debris must go somewhere.  It'll either be in the water or in the filter.  You'll also be using up more sanitizer as it must compensate for a lack of filtration.  This results in dirty-looking water and bacteria growth.

4. Poor Water Chemistry

Bad water chemistry coupled with a poor working filtration system can cause all kinds of problems for you.  Sustained high pH and high calcium hardness can cause calcification of plumbing.  Sustained high alkalinity will cause your pH to wander all around the place, not to mentioned a decrease in your chlorine's ability to kill organic matter in the pool.  

High sustained levels of chlorine can cause itchy red skin, dry scalp, and irritated lungs.  This has more to do with chloramines that are commonly found in indoor public pools.  

How To Fix Cloudy Pool Water

We know you want to get your pool back to its perfect state.  And here's how we're going to do it.  

1. Clean The Filter

Yes, it's true.  We'll never clean dirty water with a dirty or non-working filter or filtration system, so let's get the filter clean.  Backwash your sand or DE filter.  If you have a cartridge filter, make sure you take it out and clean it well.  Never use a power washer on a cartridge filter.  That's too much pressure and you're not gaining anything by using it. 

2.  Brush The Pool With A Nylon Brush

This cannot be stressed enough.  Cloudy pool water might be the first sign of an algae bloom.  This algae will try to stick to your pool surface so give it a good brushing at least twice per day. 

3. Test and Balance Your Pool Water

Bring the pH, alkalinity, and hardness into line.  Adjust your pH to 7.0-7.2.  Chlorine is more active at a slightly lower pH level.  Adjust your alkalinity to 80-120 ppm and hardness to 150-250 ppm.  Remember to maintain your CYA level at 30 - 50 ppm.  I use and recommend the Taylor K-2006 test kit.  

4. Shock Your Pool

Increase and maintain a free chlorine level of at least 20 ppm using liquid pool chlorine or bleach.  Your chlorine level will always decrease, so it's important to keep an eye on the chlorine level and keep it high. 

5. Keep Filtering

Yes, keep that pump motor on 24/7 until the entire process is finished.  All of those dead and dying brown algae particles are going to be floating in your pool water and they need a place to go.  That place it in your filter where they'll be trapped and waiting to be cleaned or backwashed out every 12 hours.   

6. Shock Your Pool Again

Let's remember that shocking a pool is a process, not an event.  Your chlorine level will always be decreasing so maintaining a high chlorine level is a must in order to kill the brown algae. 

7. Use a Clarifier

So you've made tremendous progress, but maybe your pool filter needs just a bit more oomph.  That's where a clarifer comes in handy.  At the tail-end of your process, use a clarifier to help your filter capture the smaller particles.

How To Stop Cloudy Pool Water

The best way to stop cloudy pool water is to keep a close eye on your pool chemistry and filter.  By weekly testing and balancing your chemicals and doing general pool maintenance such as vacuuming and removing debris out of the pool, you'll be able to keep your pool perfect all swimming season.