The case against column-pouring acid

Picture this: you're adding muriatic acid to your pool, and instead of evenly distributing throughout the water, it plummets straight to the bottom like a chemical depth charge, creating a highly acidic zone that could damage your pool's surface and equipment. This isn't just a theoretical concern—it's exactly what happens every time someone pours acid directly into their pool, a practice that's surprisingly common in the pool industry.

In a revealing demonstration on the Rule Your Pool Podcast, host Eric Knight used food coloring mixed with muriatic acid to visually show why this common practice is so problematic. What he discovered was both eye-opening and concerning for anyone who maintains pools professionally or as a homeowner.

The Shocking Reality of Column-Pouring Acid

Eric Knight's experiment provided a stark visual representation of what happens when acid is poured directly into a pool. Using his own 24,000-gallon pool as a testing ground, he mixed red food coloring with muriatic acid to track its movement through the water.

So here we go. Pour it on in. Now acid as you can see, it doesn't spread very much. It starts sinking. That's what it looks like. Look at that. Guys, if you are calling pouring your acid, that's what it's doing.

— Eric Knight, Rule Your Pool Podcast

The results were more dramatic than expected. Instead of dispersing evenly throughout the pool, the acid-dye mixture sank directly to the bottom, creating a concentrated acidic zone that lingered near the pool floor and main drain area. This visual demonstration clearly shows why the practice of column-pouring acid is so problematic.

Understanding the Science Behind Acid Behavior in Water

The reason acid behaves this way in water comes down to basic physics: density. Muriatic acid is approximately 18% denser than water, which means it naturally sinks when poured directly into a pool. This density difference creates several serious problems:

Concentration Issues: When acid pools at the bottom of your pool, it creates areas of extremely low pH—potentially as low as 2 or less. This is far below the safe operating range for pool water, which should typically maintain a pH between 7.2 and 7.6.

LSI Violations: The Langelier Saturation Index (LSI) measures water's tendency to be corrosive or scale-forming. When highly concentrated acid sits at the bottom of a pool, it creates what Knight describes as "dead red" LSI readings—indicating extremely corrosive conditions that can damage pool surfaces and equipment.

Uneven Distribution: Instead of neutralizing alkalinity throughout the entire volume of water, column-poured acid only affects the water in its immediate vicinity, leading to inconsistent water chemistry.

The Damage Potential: What's Really at Risk

The implications of column-pouring acid extend far beyond just poor water chemistry. When highly acidic water sits against pool surfaces, it can cause significant and costly damage:

Surface Etching: Concrete and plaster pool surfaces are particularly vulnerable to acid damage. The concentrated acid can etch and pit these surfaces, creating rough textures that harbor bacteria and algae.

Equipment Damage: Pool equipment, including pumps, heaters, and filtration systems, can suffer corrosion damage when exposed to highly acidic water.

Liner Deterioration: For vinyl liner pools, concentrated acid can cause bleaching, brittleness, and premature failure of the liner material.

What do you suppose the pH is down there? What do you suppose the LSI is down there? Look at that then go. Wow. Not good.

— Eric Knight, Rule Your Pool Podcast

The Simple Solution: Dilution Is Key

Fortunately, there's an easy fix for this problem that doesn't require any special equipment or complicated procedures. The solution is proper dilution before adding acid to your pool.

The Dilution Process:

• Use a clean bucket or container
• Fill it with pool water first (never add water to acid)
• Slowly add the measured amount of muriatic acid to the water
• Stir gently to mix
• Pour the diluted solution around the perimeter of the pool

If you dilute your acid in a bucket of water, it's not going to do that. You'll still get the same amount in assuming you're measuring it. But it changes the density so that it actually matriculates through the water and dissolves alkali before it gets to the floor.

— Eric Knight, Rule Your Pool Podcast

Why Dilution Works: When acid is properly diluted, its density becomes much closer to that of pool water, allowing it to mix more evenly throughout the water column. This means the acid can neutralize alkalinity as intended, rather than creating concentrated acidic zones.

Professional Practices and Industry Habits

One concerning aspect highlighted in the podcast is how common this poor practice is among pool professionals. Even experienced pool service technicians often pour acid around the pool perimeter without proper dilution, thinking this is sufficient.

While pouring acid around the perimeter is better than dumping it all in one spot, it's still not the best practice. The acid will still sink and create localized acidic conditions, just in multiple spots rather than one.

Better Professional Practices Include:

• Always diluting acid before adding it to pools
• Testing water chemistry regularly to avoid over-correction
• Using proper safety equipment when handling chemicals
• Educating clients about proper chemical handling
• Documenting chemical additions for tracking purposes

Safety Considerations and Best Practices

Beyond the pool damage concerns, proper acid handling is crucial for safety. Muriatic acid is a hazardous chemical that requires careful handling:

Safety Equipment:

• Chemical-resistant gloves
• Safety goggles
• Long pants and closed-toe shoes
• Work in well-ventilated areas

Chemical Handling Rules:

• Always add acid to water, never water to acid
• Pour slowly to avoid splashing
• Keep acid containers closed when not in use
• Store chemicals in cool, dry areas away from other chemicals
• Have an emergency eyewash station or hose nearby

We want to make sure that by the time it gets to the floor, it is not acid.

— Eric Knight, Rule Your Pool Podcast

Long-term Benefits of Proper Acid Addition

Making the switch from column-pouring to proper dilution offers numerous long-term benefits:

Cost Savings: Proper chemical distribution means more effective pH adjustment with less chemical waste. You'll also avoid costly repairs from acid damage.

Better Water Quality: Even chemical distribution leads to more stable water chemistry and clearer water.

Extended Equipment Life: Protecting equipment from acid damage means fewer repairs and replacements.

Improved Surface Longevity: Pool surfaces last longer when not subjected to concentrated acid exposure.

The Industry Impact: Changing Bad Habits

Knight emphasizes that acid abuse is "the number one bad habit that we see in the pool business." This widespread problem affects thousands of pools and costs pool owners significant money in unnecessary repairs and maintenance.

The demonstration serves as a powerful tool for education, providing visual proof of why proper chemical handling matters. For pool professionals, this kind of evidence-based approach to explaining best practices can help build trust with clients and justify proper service procedures.

Educational Opportunities:

• Share the demonstration video with clients
• Use visual aids to explain chemical behavior
• Implement proper dilution procedures in service protocols
• Train staff on correct chemical handling techniques
• Document the benefits of proper chemical management

Conclusion: A Simple Change with Major Impact

The case against column-pouring acid is clear and compelling. Eric Knight's simple but effective demonstration shows exactly why this common practice causes so much damage to pools across the industry. The concentrated acid creates dangerous pH conditions, violates LSI parameters, and can cause significant damage to pool surfaces and equipment.

The solution, however, is remarkably simple: dilute your acid before adding it to the pool. This basic change in procedure can prevent thousands of dollars in damage while improving water quality and extending the life of pool equipment and surfaces.

For pool professionals, adopting and teaching proper acid dilution practices isn't just about better chemistry—it's about providing better service, reducing callbacks, and building trust with clients. For pool owners, understanding why dilution matters can help them maintain their pools more effectively and avoid costly mistakes.

The next time you need to lower your pool's pH, remember Knight's demonstration and take the extra few minutes to dilute your acid properly. Your pool surfaces, equipment, and wallet will thank you for it. As the podcast emphasizes, we want to ensure that "by the time it gets to the floor, it is not acid." This simple principle can transform how we approach pool chemistry and prevent countless problems before they start.

Episode Chapters

• 00:00 Introduction and Communication Updates
• 03:15 The Promise to Destroy a Pool for Science
• 05:30 Live Demonstration: Column-Pouring Acid with Food Coloring
• 08:45 Analysis of Results and pH Implications
• 10:20 The Simple Solution: Proper Dilution
• 12:00 Conclusion and Contact Information