PoolFu

Pool Water Balance & CSI: What the Saturation Index Really Means

Fri, 27 Feb 2026 00:00:00 +0000

Water balance measures your water’s tendency to either deposit or dissolve calcium carbonate, the mineral that forms scale or etches surfaces. Balanced water is neither corrosive nor scaling, which protects your pool surfaces and equipment.

PoolFu calculates the Calcite Saturation Index, also known as the Langelier Saturation Index. It’s the same calculation with different names. We use CSI because it’s more descriptive: it tells you specifically about calcite (calcium carbonate) saturation.

The Acceptable Range

The acceptable range is -0.5 to +0.5:

Negative values (like -0.3): Water tends toward dissolving calcium
Zero: Perfectly balanced
Positive values (like +0.3): Water tends toward depositing calcium

Both ends of the acceptable range are fine. A pool at -0.4 isn’t meaningfully different from one at +0.2 in practical terms.

Where to Find Water Balance

The Water Balance card appears in your Health Score detail view. It shows:

Your CSI value prominently displayed
A visual slider showing where you fall in the -0.5 to +0.5 range
A green indicator when you’re within the acceptable range

Tap the Water Balance card to open a detailed explanation including what your specific CSI value means for your setup, the calculation breakdown showing all the factors, what Carbonate Alkalinity is and why it matters, and whether any action is needed.

What Affects CSI?

CSI is calculated from multiple readings:

pH: Higher pH increases CSI
Total Alkalinity: Higher TA increases CSI
Calcium Hardness: Higher calcium increases CSI
Temperature: Higher temperature increases CSI
CYA (Stabilizer): Affects the calculation through carbonate alkalinity
TDS (Salt): Affects the calculation through dissolved solids

Carbonate Alkalinity Explained

When you test Total Alkalinity, your kit measures everything that can neutralize acid. But not all of that alkalinity behaves the same way.

Your TA reading includes:

Carbonate alkalinity: The “real” alkalinity that buffers pH and participates in water balance
Cyanurate alkalinity: Ions from your Cyanuric Acid/stabilizer that show up on the test but don’t affect water balance the same way

For water balance calculations, PoolFu subtracts the cyanurate contribution to get the true carbonate alkalinity. This is why pools with higher CYA can show more negative CSI values, and that’s expected chemistry, not a problem.

CSI and Salt Water Generators

Salt water pools with moderate to high CYA (60-90 ppm) naturally run slightly negative CSI. This happens because:

SWG pools typically run higher CYA for chlorine efficiency
Higher CYA reduces effective carbonate alkalinity
The math correctly shows a slightly negative index

PoolFu recognizes this as expected chemistry for your setup and scores it as ideal in the Health Score. You don’t need to chase positive CSI if your setup naturally trends negative.

PoolFu Doesn’t Chase Perfect CSI

This is important: PoolFu is not trying to achieve a CSI of exactly zero.

The goal isn’t a perfect number. The goal is water that protects your surfaces and equipment without creating problems elsewhere. If your water falls within the acceptable range of -0.5 to +0.5, there’s nothing to fix. A pool at -0.3 and a pool at +0.2 are both balanced, and neither needs adjustment.

Even slightly outside this range isn’t cause for alarm. Minor imbalances are common, often temporary, and don’t require intervention. PoolFu only suggests action when the imbalance is significant enough to potentially affect your surfaces or equipment over time.

When action is needed, PoolFu considers your entire chemistry picture. It won’t suggest raising calcium to improve CSI if that would push calcium hardness above the safe range for your Surface type. It won’t suggest raising pH if that would reduce chlorine effectiveness. The Chemistry Engine evaluates all parameters together and recommends the most practical path to balance without creating new problems.

This is fundamentally different from traditional tools that check CSI against a target and flag anything off-center. Real pool chemistry requires understanding trade-offs, and sometimes “good enough” water balance is the right answer.

CSI Range	Status	Action
-0.5 to +0.5	Balanced	No action needed. Your water is protecting surfaces and equipment.
-0.7 to -0.5 or +0.5 to +0.7	Monitor	Don’t panic. Minor imbalances are common and usually self-correct.
Below -0.7 or above +0.7	Adjust	Too low: raise calcium or pH gradually. Too high: lower pH or reduce calcium.

Cold Weather and CSI

When water temperature drops below 50°F (10°C), achieving perfect water balance may be impossible within safe calcium ranges. PoolFu excludes CSI from the Health Score calculation in cold weather mode, so you won’t be penalized for imbalance that can’t reasonably be fixed.

Important Context

CSI is about long-term surface and equipment protection, not immediate safety. A slightly corrosive or scaling pool is still safe to swim in. Focus on sanitizer and pH for safety; treat CSI as a maintenance consideration rather than an urgent concern.

The Water Balance card uses informational blue colors rather than red/yellow/green traffic lights. This is intentional. Water balance is nuanced, and we don’t want to create unnecessary alarm over values that are perfectly acceptable.

The Unity Framework, Your Pool as a Chemistry System

Thu, 29 Jan 2026 00:00:00 +0000

If you’ve been around for long enough (like we have, and yes we’re all old!), you might remember those circular disc slide calculators that came with test kits, in fact many still have them. You’d align your pH reading with your alkalinity, turn the disc, and read off a dosing recommendation through a little window. These devices were clever bits of analog engineering, essentially circular slide rules adapted for pool chemistry. Similar calculators existed for photography exposure, aviation flight planning, and engineering calculations going back to the 1930s and earlier.

The genius of these tools was also in their limitation. Each calculation happened in isolation. You’d do one for pH adjustment, another for chlorine dosing, maybe a third for water balance. The disc couldn’t consider all your readings in any uniform way because the physical mechanism only allowed for pairwise relationships. Line up two numbers, get one answer.

When pool chemistry went digital, most calculators simply replicated this approach in software. Enter your pH, get a recommendation. Enter your chlorine and Stabilizer, get another recommendation. Each parameter evaluated against its own ideal range, flagged if outside the lines. The circular slide rule became a series of if-then statements, but the fundamental thinking remained unchanged. Parameters as independent variables, each with static targets.

This approach works well enough for simple situations. But pool chemistry is more interconnected than these tools acknowledge, and that’s where the guidance starts to break down.

The Problem with Parameter-by-Parameter Thinking

Your pool is an interconnected system where everything affects everything else. The pH influences how effective your chlorine is. Your stabilizer level changes what “enough chlorine” even means. Water temperature shifts what “balanced” looks like. The Surface type of your pool determines how much calcium you actually need. These relationships matter, and understanding them is what separates useful guidance from generic number-checking.

Consider two pools with identical chlorine readings of 3 ppm. One has a salt water generator and stabilizer at 70 ppm. The other uses liquid chlorine with stabilizer at 30 ppm. Same chlorine number, completely different situations.

Cyanuric Acid binds to chlorine molecules, protecting them from UV degradation but also reducing their sanitizing power. The higher your stabilizer, the more total chlorine you need to maintain the same level of active, killing chlorine. At 70 ppm CYA, a reading of 3 ppm Free Chlorine means most of that chlorine is bound up and unavailable. At 30 ppm CYA, more of it remains active. The first pool with its salt water generator is producing chlorine continuously and maintaining adequate sanitation despite the higher stabilizer. The second pool is already creating conditions favorable to algae because its chlorine, dosed intermittently, can’t keep up with the demand created by lower but still significant CYA binding.

A chart that says “3-5 ppm chlorine is ideal” misses this entirely. The number 3 doesn’t mean the same thing in both pools.

This pattern repeats across parameters. pH has a textbook ideal around 7.4 to 7.6, but where you actually want to be within that range depends on your water’s overall balance. Total Alkalinity acts as a buffer for pH, but the ideal TA level varies based on your sanitizer type and whether you’re running a pool or a spa. Calcium Hardness targets depend on your surface material, your water temperature, and what the rest of your chemistry is doing.

The circular slide calculator couldn’t handle this complexity. Neither can its digital descendants.

Water Balance and the Saturation Index

Water balance is where the interconnection becomes most apparent and where parameter-by-parameter thinking fails most visibly.

The Calcite Saturation Index, sometimes called the Langelier Saturation Index, combines pH, alkalinity, calcium hardness, and temperature into a single number that tells you whether your water wants to dissolve minerals or deposit them. A negative CSI means water is aggressive and will pull calcium from wherever it can find it, including your plaster, your heater’s heat exchanger, and your pump seals. A positive CSI means water is supersaturated and will deposit scale on surfaces, clogging equipment and creating rough spots on pool walls.

The target is balance, typically a CSI near zero, where water is neither aggressive nor scaling.

Here’s where traditional tools create confusion. You might see every individual parameter showing green checkmarks while a separate water balance indicator shows a corrosion warning. Your pH card says “ideal” but your Saturation Index says the water is eating your plaster. Which should you believe?

Both are telling the truth from their limited perspective. The pH really is within its standalone ideal range. The water really is aggressive. These facts coexist because CSI depends on the interaction of multiple parameters, not on any single one. A pH of 7.4 might contribute to balanced water in one pool and corrosive water in another, depending on what’s happening with alkalinity, calcium, and temperature.

Temperature deserves special attention here. The same chemistry that produces balanced water at 75°F (24°C) will produce scaling water at 104°F (40°C). Calcium becomes less soluble as temperature rises, which means hot water can hold less calcium in solution before it starts depositing. This is why hot tubs and spas need to target slightly negative CSI values. Water that would be perfectly balanced in a cooler pool will actively deposit scale at spa temperatures. Anyone who has seen the inside of a neglected spa heater understands this viscerally.

Static targets don’t account for any of this. The chemistry itself changes with conditions.

The Unity Framework

How PoolFu Approaches This Differently

Unity

pH Acidity

FC Chlorine

TA Alkalinity

CYA Stabilizer

CH Hardness

CSI Balance

This is the problem PoolFu was built to solve. Rather than evaluating parameters against static charts, the app treats your water chemistry as one integrated system through what we call the Unity Framework.

The name reflects our philosophy. Parameters and water balance aren’t separate concerns that compete with each other. They’re aspects of a single system that need to be understood together. When you enter your readings, the Chemistry Engine evaluates each parameter in the context of everything else happening in your water. Your equipment, your surface type, your stabilizer level, your water temperature. The same number gets interpreted differently based on your specific setup, because that’s how pool chemistry actually behaves.

When the app suggests adjusting pH, it’s considering both the parameter itself and how that change affects overall water balance. When balance is off, it identifies the most practical way to correct it without pushing other readings out of range. This coordination happens automatically. You don’t see conflicting advice because the system doesn’t generate conflicting advice.

The Chemistry Engine handles all the underlying calculations, maintaining what we believe is the most comprehensive model of pool chemistry relationships available in a consumer app. It knows that chlorine effectiveness depends on CYA. It knows that calcium targets vary by surface type. It knows that temperature affects saturation behavior. These relationships are built into every recommendation rather than bolted on as afterthoughts.

One System

Not Separate Charts

Parameters and water balance evaluated together. The same chlorine reading gets different guidance at different stabilizer levels, because that's how the chemistry works.

Your Setup

Not Generic

Surface type, equipment, temperature, and sanitizer method all factor into every recommendation. No two pools get identical advice unless they're genuinely identical.

No Conflicts

By Design

Because the Chemistry Engine evaluates everything simultaneously, it never suggests fixing one parameter in a way that breaks another.

Your Equipment Should Do Its Job

Context-awareness extends to your equipment. If you have a salt water generator and your chlorine is low, the first suggestion shouldn’t be “add bleach.” Your pool makes its own chlorine. The equipment should handle it.

PoolFu knows what you have and recommends accordingly. For salt water pools running low on chlorine, the guidance starts with adjusting your generator output or extending run time. Chemical additions come into play when the equipment genuinely can’t keep up, not as the default response. This seems obvious when you say it out loud, but it requires the system to understand equipment capabilities rather than just treating every pool as a vessel that needs chemicals added to it.

The same thinking applies throughout. Pools with heaters get different calcium guidance because scale buildup affects heat exchangers more directly. Pools with water features get context about why pH might be drifting upward from aeration. The recommendations reflect your actual setup rather than assuming a generic pool that doesn’t exist.

Surface Type and Temperature

Your pool’s surface material affects what “correct” chemistry looks like, particularly for calcium hardness.

Plaster and pebble surfaces need calcium saturation. If your water is undersaturated with calcium, it will pull minerals out of the plaster itself, gradually etching and roughening the surface. This is why plaster pools target higher calcium levels, typically 250 to 350 ppm.

Vinyl and fiberglass don’t have the same surface protection needs. The liner or shell doesn’t care about calcium saturation the way plaster does. But your equipment still needs protection. Aggressive water attacks heater elements, pump seals, and any metal components in the circulation system regardless of what your pool walls are made of. So even pools without mineral surfaces need some minimum calcium level, just not as high as plaster requires.

The Unity Framework incorporates surface type into its balance calculations. When the theoretically optimal calcium level for perfect CSI falls outside what’s safe or sensible for your surface, the system adapts. Maybe calcium is already at the maximum reasonable level for fiberglass, so pH becomes the adjustment path instead. The goal is achievable balance within your pool’s actual constraints rather than theoretical perfection that would damage something else.

Temperature affects these calculations significantly. Cold water naturally runs more negative CSI because of how calcium solubility works at lower temperatures. A pool at 50°F (10°C) that shows slightly negative CSI might be behaving exactly as physics dictates, not suffering from a chemistry problem that needs solving. Hot spas face the opposite challenge, where even small positive CSI values can mean active scaling.

PoolFu adjusts its targets and its guidance based on water temperature because the underlying chemistry genuinely changes with conditions. Recommendations for a heated spa at 104°F (40°C) look different from recommendations for an unheated pool at 68°F (20°C), as they should.

Expected Chemistry vs. Problems to Solve

One of the more subtle aspects of the Unity Framework is recognizing when unusual-looking readings are actually expected for a particular setup.

Salt water generators with proper stabilizer levels will naturally show slightly negative saturation index values. This happens because of how CYA affects the calculation. Cyanuric acid reduces the effective carbonate alkalinity that factors into CSI, pulling the index negative. The water isn’t actually corrosive in the way the raw number might suggest. It’s behaving exactly as the chemistry predicts for that equipment and stabilizer combination.

Most tools would flag this as a problem. The CSI is negative, therefore the water is aggressive, therefore you need to add calcium or raise pH. But following that advice for an SWG pool with proper stabilizer would push other parameters out of their ideal ranges while solving a problem that doesn’t actually exist.

PoolFu recognizes these patterns and doesn’t create unnecessary alarm about chemistry that’s working correctly. When your water balance is exactly where it should be given your setup, the app tells you that rather than suggesting interventions that would make things worse.

This kind of recognition requires understanding the relationships between parameters, equipment, and expected outcomes. It’s not something you can encode in a circular slide calculator or its digital equivalent. The system needs to model how the pieces fit together.

Patterns Over Time

With enough test records, patterns start to emerge that help explain recurring issues.

Maybe your pH consistently drifts upward over weeks of testing. For a salt water pool, this is a signature behavior. The electrolysis process that generates chlorine also produces sodium hydroxide as a byproduct, which raises pH. Understanding this explains why you’re always adding acid and suggests that running slightly lower TA might reduce the buffering that makes pH harder to move.

Maybe your stabilizer keeps climbing even though you’re not adding any. This usually means you’re using Dichlor or Trichlor tablets, which contain cyanuric acid as part of their formulation. Every dose of chlorine is also a dose of stabilizer. Eventually CYA accumulates to the point where it’s hampering chlorine effectiveness, and the only solution is partial drain and refill to dilute it down.

PoolFu watches for these patterns and provides insights about what’s happening over time. This helps you understand the recurring “why” behind certain issues rather than treating the same symptoms repeatedly without addressing root causes.

The app doesn’t pretend to know things it doesn’t know. If you haven’t entered your salt generator’s output percentage, it won’t assume a value and calculate around it. Recommendations stay grounded in what you’ve actually told the system about your setup.

This matters because bad assumptions lead to bad advice. Guessing that your SWG is running at 50% output when it’s actually at 80% produces a completely different recommendation than the truth would. Rather than fabricate certainty, the app acknowledges what’s known and what isn’t.

For genuinely complex situations, we don’t pretend the app replaces professional judgment. Some pool problems require someone on site looking at the water, the equipment, and the surfaces. But for the vast majority of routine maintenance decisions, having a tool that actually understands chemistry relationships beats having a fancy version of a circular slide calculator.

The Goal

Pool chemistry shouldn’t feel like a mystery that requires memorizing charts or cross-referencing multiple sources. It shouldn’t generate contradictory advice that leaves you wondering which recommendation to follow. It shouldn’t treat every pool as identical when they’re clearly not.

PoolFu aims to be the knowledgeable friend who actually understands how pools work, considers your specific situation, and gives you guidance that holds together as a coherent whole. Your water is a system. The Unity Framework and Chemistry Engine exist because the tools that help you manage it should understand that too.

The circular slide calculator was a brilliant solution for its era. But your pool deserves better than forty-year-old thinking dressed up in a modern interface.

John Wojtowicz, The Chemist Who Gave Us Modern Pool Science

Wed, 28 Jan 2026 00:00:00 +0000

If you’ve ever used a pool calculator that adjusts for Cyanuric Acid, you’ve benefited from John Wojtowicz’s work. If your app corrects Total Alkalinity readings to account for stabilizer, that’s his formula. If anyone has ever explained to you why the pool industry’s Saturation Index needed updating, they were channeling research he published in the late 1990s.

Most pool owners have never heard his name. The science they rely on every day traces back to papers he wrote after retiring from a 32-year career in industrial chemistry.

John A. Wojtowicz was born in Niagara Falls, New York on October 12, 1926. When he was ten, during the worst years of the Great Depression, he spent several years in an orphanage before going to live with his aunt and uncle. He graduated from Trott Vocational High School in 1945, then earned a B.S. in Chemistry from the University of Buffalo and an M.A. from Niagara University.

He worked for eleven years as a laboratory technician at DuPont in Niagara Falls. After two years in the Army, he joined Olin Corporation as a Research Chemist. In 1959, Olin transferred him to their research laboratory in New Haven, Connecticut, where he worked as Senior Research Chemist until his retirement in 1991.

His career at Olin produced 56 U.S. patents and numerous foreign patents. He authored fifty journal articles and wrote six chapters for the Kirk-Othmer Encyclopedia of Chemical Technology, the standard reference work for industrial chemistry. His encyclopedia entries covered Hypochlorous Acid, hypochlorites, Chloramines, bromamines, and cyanuric acid. He presented papers at national meetings of the American Chemical Society. He was, by any measure, a serious industrial chemist working at the highest levels of his field.

Then he retired. And he turned his attention to swimming pools.

The Problem He Saw

The swimming pool industry had been using the Langelier Saturation Index (LSI) since the early 1960s to predict whether water would scale or corrode. The LSI originated in the 1930s with Dr. Wilfred Langelier, a sanitary engineering professor at UC Berkeley who developed it for municipal water systems. His concern was pipe corrosion in closed-loop industrial applications.

The pool industry adopted his index and adapted it. The adaptation involved simplification. Tables of factors replaced the underlying thermodynamic calculations, and approximations accumulated. By the time Wojtowicz examined the formula the industry was using, it had drifted considerably from the original science.

He found several problems. The temperature factors in published tables had been miscalculated and then copied into every major pool operation textbook. The formula used a constant for total dissolved solids that assumed 500 ppm, which made it unreliable for saltwater pools. Most significantly, it treated total alkalinity as if it were the same as Carbonate Alkalinity.

In pools using cyanuric acid (CYA) as a Stabilizer, this last issue mattered enormously. Cyanuric acid ionizes in water to form Cyanurate, which is alkaline. When you measure total alkalinity with a standard test kit, you’re measuring both carbonate alkalinity and cyanurate alkalinity combined. The saturation index cares only about carbonate alkalinity, because that’s what determines calcium carbonate solubility. Using the wrong number means your index calculation is wrong, sometimes significantly so.

Wojtowicz worked out the correction. At typical pool pH, roughly one-third of your cyanuric acid concentration should be subtracted from your total alkalinity reading to get carbonate alkalinity. At pH 7.4 with 100 ppm CYA, a total alkalinity reading of 100 ppm actually represents a carbonate alkalinity of about 69 ppm. The difference matters. Water that looks balanced on paper might actually be corrosive.

The Papers

Between 1995 and the early 2000s, Wojtowicz published extensively in the Journal of the Swimming Pool and Spa Industry. His output was remarkable for someone in retirement. A nine-part series on swimming pool water balance rebuilt the saturation index from first principles. He documented the cyanurate alkalinity correction with laboratory experiments and field tests. He wrote about buffer chemistry, calcium carbonate precipitation potential, carbon dioxide loss, and the thermodynamic basis underlying all of it.

The papers are dense. They contain derivations, equilibrium constants, ionization fractions, and activity coefficients. They cite Plummer and Busenberg’s 1982 work on calcite solubility, O’Brien’s 1972 Harvard thesis on chlorinated isocyanurates, and the primary literature going back decades. This was peer-reviewed science applied to an industry that had been running on rules of thumb.

He also wrote practical papers. Surveys of sanitizers and sanitation systems. Product information summaries. Chemical adjustment dosing guides. Safe storage and shipping temperatures for pool chemicals. The theoretical work supported practical application.

His paper on the applicability of the Langelier Saturation Index to swimming pools directly addressed whether an index designed for closed pipes even made sense for open bodies of water. Some argued it didn’t. Dr. Thomas, Langelier’s successor at UC Berkeley, had been quoted saying the index “has no significance to open bodies of water.” Wojtowicz showed experimentally that a properly calculated saturation index was indeed applicable to pools, provided you used the correct formula with appropriate corrections.

Why This Matters Now

Every serious pool chemistry resource today cites Wojtowicz. Industry trade associations reference his revised saturation index equation. Test kit manufacturers acknowledge his contributions to understanding pool water chemistry. His papers are the foundation that modern pool science rests upon.

CYA ÷ 3

The Rule

His correction factor table, validated through laboratory titrations and a four-week spa test. Now used by every serious pool calculator.

LSI Tables

Corrected

The industry's published saturation index tables contained calculation errors. His papers documented every one.

TDS Math

For Saltwater

Saltwater pools need different handling in saturation calculations. He worked out the thermodynamics.

When you use a modern pool app that gives you a CSI or corrected LSI, the underlying science traces to his publications. When someone explains that cyanuric acid affects your alkalinity reading, they’re passing along his research. When a forum post debunks outdated pool store advice using actual chemistry, the chemistry often comes from his work.

PoolFu’s Chemistry Engine

PoolFu’s chemistry engine is built on Wojtowicz’s foundational research. His corrected saturation index equation, his work on carbonate alkalinity adjustment for cyanuric acid, and his temperature-dependent calculations all inform how the app evaluates your water.

When PoolFu calculates your water balance, it’s using science that traces directly to his papers. The app doesn’t just apply static ranges from an outdated chart, it implements the thermodynamic relationships he documented, adapting targets based on your actual water temperature and chemistry.

This is what he spent his retirement building: a scientific foundation rigorous enough that software could implement it correctly. That foundation now runs inside the phones of pool owners who’ve never read a chemistry paper but benefit from his work every time they test their water.

The Chlorine Lock Question

Wojtowicz’s papers also provide ammunition against persistent myths. The notion of “chlorine lock”, the idea that high cyanuric acid renders chlorine completely ineffective, has been floating around the pool industry for decades. It originated with 1960s laboratory studies that showed cyanuric acid slowed chlorine’s kill time against bacteria.

The studies were real. Anderson in 1965 and Fitzgerald and DerVartanian in 1969 documented that CYA reduced bactericidal speed in controlled conditions. Anderson himself cautioned that his results came from laboratory conditions and should be used with caution if extended to actual swimming pool operation. Field studies by other researchers found that in real pools, with real organic loads and nitrogen compounds present, the relationship was more complex. Chlorine in stabilized pools could actually outperform unstabilized pools under certain conditions.

Wojtowicz’s papers on chlorine chemistry, the chloroisocyanurate equilibrium, and the interaction between CYA and available chlorine provide the scientific foundation for understanding what actually happens. Higher CYA does require proportionally higher Free Chlorine to maintain the same sanitizing power. The relationship is well-defined and calculable. The idea that chlorine becomes completely “locked” at some threshold is a misreading of the science.

A Life in Chemistry

Wojtowicz died on May 19, 2020, at 93. He had spent his retirement in Arizona, where he competed in the World Senior Games in Utah and the Arizona Senior Olympics. He was a Notre Dame football fan. He left three children, seven grandchildren, and three great-granddaughters.

His obituary in the Hartford Courant listed his patents, his encyclopedia chapters, his journal articles, and his book, The Chemistry and Treatment of Swimming Pool and Spa Water. It mentioned his consulting work and his service as an expert witness in chemical product liability cases. It noted that he had started his education after surviving childhood in a Depression-era orphanage.

The pool industry he contributed to so significantly after retirement rarely mentions him by name. His papers are cited in technical documents and wiki footnotes. His formulas run silently inside calculators. His corrections are applied automatically by apps that never explain where the math came from.

That’s how science often works. The person who did the foundational research fades into the background while the practical applications spread everywhere. But for those who want to understand pool chemistry at a deeper level, who want to know why we adjust alkalinity for CYA or why the saturation index matters, Wojtowicz’s papers remain the primary source.

They’re freely available. The Journal of the Swimming Pool and Spa Industry archives are hosted at poolhelp.com. Anyone curious enough to read them will find careful science, clearly documented, applicable to problems pool owners face every day.

First Principles

He gave the industry a foundation built on thermodynamics rather than approximation. Formulas derived from science rather than copied from outdated tables. An understanding of pool chemistry that actually matches what happens in the water.

Most pool owners will never read his papers. They’ll use apps and calculators that incorporate his work without attribution. They’ll follow advice that traces back to his research without knowing it. And their pools will be better maintained because a retired industrial chemist decided to apply serious science to a field that needed it.

Paper CYA and Carbonate Alkalinity

"The Effect of Cyanuric Acid and Other Interferences on Carbonate Alkalinity Measurement", the foundational paper that established the correction factor.

Paper Swimming Pool Water Balance

Part of his nine-part series rebuilding saturation index theory from first principles. Part 7, "A Revised and Updated Saturation Index Equation," is the key reference.

Archive JSPSI Technical Articles

Complete archive of the Journal of the Swimming Pool and Spa Industry, with Wojtowicz's original papers available as PDFs.

Obituary Hartford Courant Obituary

Published June 2020, documenting his life from Niagara Falls to Arizona, his 56 patents, and his contributions to pool chemistry.