Managing a commercial or public pool is no small task. Between daily testing, equipment maintenance, regulatory compliance, and, of course, keeping pool guests happy and healthy, you have to stay ahead of issues that can compromise water quality, safety, or appearance. 

But when issues do happen, from time to time, it helps to be prepared with the steps you need to take to quickly remediate them, minimize damage and pool closure time, and reopen safely.

A chlorine wash is an intensive cleaning method that can play a vital role in keeping your pool healthy, attractive, and fully operational, especially in high-use settings like apartment complexes, hotels, and community associations like HOAs. From algae to cleaning up fecal contaminations, knowing why, when, and how to chlorine wash your pool is important for pool operators, owners, and managers to know. 

What Is a Pool Chlorine Wash?

A chlorine wash is a deep-cleaning process where you apply liquid chlorine (sodium hypochlorite) directly to a drained pool’s surfaces, including its walls, floor, and steps. Chlorine is a strong oxidizer that disinfects the pool shell, removing embedded algae, bacteria, mold, organic stains, and other persistent contaminants that regular cleaning and chemical balancing can’t eliminate.

It is different from, and milder than, an acid wash, which uses muriatic acid to etch and strip the pool surface. While acid washes are more aggressive and used to remove heavy, stubborn stains, chlorine washes are ideal for biological cleaning: killing spores and sanitizing stubborn areas prone to algae and biofilm.

When Should You Chlorine Wash a Commercial or Public Pool?

Chlorine washing is a step above typical pool cleaning and maintenance, and isn’t something you’ll need to do every day or every week. For public, commercial, and community pools, consider a chlorine wash when you notice:

• Persistent algae problems: If green, black, or yellow algae keep returning despite balanced water chemistry and proper filtration, it may indicate algae is rooted into the surface.
  
  
• Seasonal pool openings: For facilities that see seasonal use, such as HOAs, community pools, or hotels that winterize pools, a chlorine wash before reopening can eliminate mold, mildew, and algae growth that occurred while covered or inactive.
  
  
• Post-contamination events: After a major fecal accident or storm-related flooding, your local health department or codes may either recommend or require a chlorine wash to sanitize the pool.
  
  
• Visual staining or discoloration: While a chlorine wash won’t remove heavy or deep surface stains, organic stains from leaves, sunscreen, or algae can be removed with a chlorine wash, restoring a cleaner, more appealing pool appearance. This is also a good step to take to remove stains before trying an acid wash, which is aggressive and not without risk.
  
  

Benefits of a Chlorine Wash for Commercial Pools

The cleanliness and appearance of your pools directly impacts your guests’ experience, as well as their overall impression of your facility, and with it, your reputation. Chlorine washing can be a good tool in your kit to keep a clean, healthy pool.

• Improved Health and Safety: Pools that serve hundreds of swimmers a week are not easy to keep balanced. Algae, mold, and biofilm are more than aesthetic concerns: they can harbor harmful bacteria and cause slippery surfaces that increase the risk of accidents. A chlorine wash helps reset the pool surface to a hygienic standard, reducing health code violations and safety incidents.
  
  
• Better Visual Impression: Nobody wants to swim in a murky, cloudy, or stained pool, and guests at hotels or residents in upscale apartments or HOA communities have understandably high expectations for pool appearance. A chlorine wash can brighten a dingy pool, remove unsightly stains, and improve overall water clarity once refilled.
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  Compliance and Prevention: Your local health department may require a deep cleaning of pools after contamination or prolonged inactivity. Chlorine washing helps ensure you're meeting local requirements and preventing larger issues that could force unexpected closures or lead to fines.

What’s Involved in a Pool Chlorine Wash?

A chlorine wash typically includes the following steps:

1. Turn off the pool pump and filtration system, then use a skimmer or vacuum to remove any visible debris (such as leaves).
   
   
2. Drain the pool completely. This should be done by trained professionals only!
3. Dilute the chlorine by mixing a ratio of 1 gallon liquid chlorine to 2 gallons water. This gives you a mixture that’s strong enough to sanitize, disinfect, and oxidize algae and contaminants, but not so strong it will harm pool surfaces.
   
   
4. Apply the diluted chlorine by liberally pouring it down the sides of the pool, allowing it to coat the sides and bottom. You can help spread it across the pool surfaces using brushes or sprayers.
   
   
5. Allow it to sit for a specific time (often 24 hours), depending on severity.
   
   
6. Scrub the surfaces to help dislodge and remove algae and any other organic material.
   
   
7. Rinse thoroughly with fresh water and remove any residue.
   
   
8. Refill the pool, balance chemicals, and restart filtration systems.
   
   

Note: Only trained professionals, such as your on-staff certified pool operator, should perform chlorine washes. Handling concentrated chlorine improperly can pose serious health and safety risks.

How to Know if You Need a Chlorine Wash or an Acid Wash

While both chlorine washing and acid washing are deep-cleaning procedures, they serve different purposes:

Chlorine wash: 

The primary purpose of a chlorine wash is to sanitize and remove organics, including bacteria, algae, mold, and organic debris. This makes sense if you think about chlorine’s usual role in sanitizing pool water. To perform a chlorine wash, you will use liquid chlorine. A chlorine wash has a shorter downtime: typically 1-2 days. It does not have any effect on pool surfaces. 

Acid wash:

The primary purpose of an acid wash, on the other hand, is to remove mineral stains, including from iron, calcium, and rust, and scale. You use an acid–specifically muriatic acid (also called hydrochloric acid). Because it is an acid, it does lightly etch the surface of pool plaster and should not be done too frequently. There is more to do to prepare the surface before an acid wash, and because of this, acid washing has a longer downtime than chlorine washing. 

Acid washing is the most aggressive stain removal option there is, and while it may be necessary in some cases, it’s best to carefully evaluate if your pool really needs it. Muriatic acid is highly corrosive and can damage pool surfaces; acid washing also costs anywhere between $600-$3000.

If you have a heavy algae problem, you may first want to chlorine wash the pool to kill and remove the algae, then follow it up with an acid wash to remove staining. You can also try other alternatives–such as diamond washing or pressure washing–after the chlorine wash, to see if it can help you avoid acid washing altogether. A professional pool service can also help assess which treatment is appropriate.

Chlorine Washing Best Practices for Pool Managers

• Schedule during low-use periods: Coordinate washes in the off-season or early in the week when traffic is lightest.
  
  
• Communicate with residents or guests: Let pool guests know in advance about any closures. Be transparent about why you’re performing a chlorine wash, as that transparency helps build and maintain trust. Your guests will want to know when (and why) you’re taking extra steps to ensure a clean, healthy, and safe pool. By keeping them in the loop, you’re demonstrating that you are on top of managing any issues that arise.
  
  
• Hire licensed pool professionals: Always use certified technicians or operators who are knowledgeable about commercial pool operations, pool chemistry, and local health regulations.
  
  
• Maintain proactive care: A chlorine wash is not a substitute for regular maintenance. It should be part of a comprehensive pool care strategy.
  
  

Final Thoughts on Pool Chlorine Washing

A chlorine wash may not be part of your daily operations, but it is a powerful tool in your maintenance arsenal. Used appropriately, it can even be a strategic move for commercial and public pools: improving cleanliness, extending surface life, and ensuring your facility stays compliant and visually appealing. Whether you're managing a busy hotel pool or an HOA community pool, periodic chlorine washes can help protect your investment and keep your guests happy and safe.

Once you do perform your chlorine wash–whether it’s at the beginning of a season or following a contamination event–it’s as critical as ever to stay on top of your pool water quality and chemistry. Balanced, clean pool water will help ensure algae doesn’t return, stains don’t build up again, and pool guests enjoy their swims. Remove debris and brush pool surfaces regularly, and ensure pH, alkalinity, and other key water parameters are in the ideal range.

From maintaining ideal pH to calculating precise chemical adjustments, PoolSharkH2O is designed to help make keeping pool water sparkling clean and safe easier. Our simple-to-use and mobile app makes testing pool water and calculating chemical adjustments easy by doing the complex math equations for you, ensuring you or your staff use the exact, correct amount of chemicals you need. 

Test and adjustment records are locked automatically and saved digitally, so you can always go back to reference and are always Health Department compliant. When paired with digital LaMotte WaterLink SpinTouch, pool water tests can be performed by staff in 60 seconds and are certified to NSF Level 1 accuracy–saving you time, money, and even pool chemicals.