A discussion on pH

Why pH Is More Than Just a Number on Your Test Strip

If you've ever looked at a crystal-clear pool and assumed the chemistry was perfect, think again. As pool professionals Wayne and Steve remind us on the Talking Pools Podcast, "You can't tell if the chemistry is good by looking at it." This fundamental truth leads us into one of the most misunderstood aspects of pool maintenance: pH management.

While most pool owners know they need to test pH, few understand its far-reaching impact on sanitizer effectiveness, equipment longevity, and water clarity. Today, we're breaking down everything you need to know about pH – from how different chlorine products affect your water balance to why metal staining might be lurking just one chemical addition away.

The Sanitizer pH Spectrum: Not All Chlorines Are Created Equal

One of the biggest revelations from this episode is how dramatically different sanitizers affect your pool's pH. Understanding these differences is crucial for maintaining proper water balance without constantly fighting pH swings.

Each one of the forms of chlorine and bromine are great, but they all have their own unique pH. And it can go as low as trichloride, for example, which can be anywhere from 2.8 to 3.5, depending upon the manufacturer, to the opposite end of the pH scale, where you've got all the hypochlorites.

— Wayne, Talking Pools Podcast

Here's the breakdown of common sanitizers and their pH levels:

• Trichlor (tablets): Extremely acidic at 2.8-3.5 pH
• Sodium Hypochlorite (liquid chlorine): Very alkaline at 10-13 pH
• Cal-hypo (shock): High alkaline at 11-12 pH
• Dichlor: Nearly neutral at 6.6-6.8 pH
• Bromine: Acidic at 4.6-4.8 pH

This knowledge transforms how you approach pool maintenance. Instead of viewing pH adjustment as a separate task, you can strategically choose sanitizers that work with your water's current state.

The Sweet Spot: Why 7.4-7.6 pH Matters

The target pH range of 7.4-7.6 isn't arbitrary – it's based on human physiology and optimal chlorine efficiency.

The reason being why we want it there is because the saline in our tears is at about 7.4. So we want to keep the water as close to the human body as possible to provide an enjoyable swimming experience for the people in the pool.

— Steve, Talking Pools Podcast

But comfort isn't the only consideration. This pH range also ensures:

• Maximum sanitizer effectiveness
• Prevention of equipment corrosion
• Optimal chemical distribution
• Minimal eye and skin irritation

When pH drifts outside this range, you're not just dealing with swimmer discomfort – you're setting the stage for more serious problems.

The High pH Problem: When Liquid Chlorine Becomes Your Enemy

Liquid chlorine's popularity as a sanitizer creates a common scenario: using it repeatedly pushes pH higher and higher. While this isn't immediately catastrophic, it creates a cascade of problems.

When I show up at a pool and the pH is a little bit high, I'm not like shaking my head. You know, I'm like, all right, we can deal with this. No big deal... But when I show up and a pool, especially a commercial pool is low in the 7.2 or 7.0 range, that is like a you have to pull an immediate stop and fix that right away.

— Steve, Talking Pools Podcast

High pH problems include:

• Cloudy water, especially with high alkalinity (above 180 ppm)
• Reduced sanitizer effectiveness
• Scale formation on surfaces and equipment
• Metal precipitation and staining

The irony is that liquid chlorine's high pH makes it perfect for pools with low pH and low chlorine – you solve two problems with one product. But continued use requires balancing with acid additions.

The Hidden Danger: Metal Contamination and pH Swings

Perhaps the most eye-opening part of the discussion centers on how pH affects metal solubility. This creates scenarios where pool owners unknowingly set themselves up for dramatic staining events.

The process works like this:

1. Low pH water becomes acidic and leaches metals from heaters, pipes, or source water
2. These dissolved metals remain invisible in the acidic water
3. A shock treatment or pH spike causes metals to precipitate out of solution
4. Staining appears seemingly overnight

The higher the pH, the more metals come out of solution. They're no longer soluble. They're insoluble. And what happens is you've got copper, you've got iron, and you've got sometimes manganese in there that come out of solution and stain the surfaces.

— Wayne, Talking Pools Podcast

Metal staining manifests in various ways:

• Copper: Blue-green stains, teal discoloration, or yellow "Mountain Dew" colored water
• Iron: Brown, orange, or rusty-colored stains and water
• Manganese: Purple water or purplish-black freckles on surfaces

The challenge is that metals above 0.3 ppm can cause staining, and many municipal water supplies contain copper around 0.1-0.5 ppm. Well water often contains much higher levels of all three metals.

Practical pH Management Strategies

Understanding pH's complexity leads to better management strategies. Here are the key approaches discussed:

Strategic Sanitizer Selection: Choose your sanitizer based on your pool's current pH state. Low pH pools benefit from liquid chlorine's alkaline boost, while high pH situations call for trichlor or acid additions before shocking.

Proactive Metal Testing: Regular testing for copper, iron, and manganese helps identify problems before they become visible. This is especially crucial for pools with heaters or well water sources.

Balanced Shocking: When using high-pH shock products, consider pre-treating with acid or using dichlor shock to minimize pH spikes that precipitate metals.

Equipment Monitoring: Watch for signs of heat exchanger deterioration, such as small metal flakes appearing after backwashing. Even properly balanced water can gradually affect old equipment.

Alkalinity Management: Keep alkalinity in the 80-120 ppm range. High alkalinity (above 180 ppm) combined with high pH creates the perfect storm for cloudy water and scaling.

The Bottom Line on pH Management

pH management isn't just about keeping a number in range – it's about understanding the interconnected web of water chemistry. Every chemical addition affects pH, and every pH change affects sanitizer efficiency, equipment longevity, and the potential for problems like metal staining.

The key insight from Wayne and Steve's discussion is that successful pool maintenance requires thinking systemically. When you understand that your choice of sanitizer affects pH, that pH affects metal solubility, and that metal contamination can create staining disasters, you're equipped to make better decisions.

Rather than treating pH as an isolated parameter, view it as the central hub around which all other aspects of water chemistry revolve. This perspective transforms routine maintenance from a series of reactive adjustments into a proactive strategy for long-term pool health.

Remember, clear water doesn't always mean balanced water. By understanding pH's role in the bigger picture, you're better equipped to maintain not just clear, but truly healthy pool water that protects both swimmers and equipment for years to come.

Episode Chapters

• 00:00 Introduction and Thanksgiving Greeting
• 02:30 Why pH Matters More Than You Think
• 05:15 Different Sanitizers and Their pH Levels
• 08:45 The Ideal pH Range and Why
• 12:20 High vs Low pH Problems
• 18:30 Metal Contamination and pH Relationship
• 25:10 Identifying Different Types of Metal Staining
• 32:45 Practical Management Strategies