Built by a pool owner

Why I built PoolChem Tracker

In 2022, my family built a house, and then built an inground saltwater pool from scratch.

When we filled it for the first time, I knew almost nothing about pool chemistry. Like most new pool owners, I relied on the pool store and a handful of apps. The advice often conflicted, the recommendations did not seem to solve the problems I was having, and I still did not understand why my water kept getting out of balance.

I am not a chemist by training. My background is in business, and I am the kind of person who turns everything into a spreadsheet.

From the very first week, I logged every water test, every chemical addition, and every recommendation from the pool store. After a few months, patterns started to emerge. They did not match what I was being told.

Eventually, I figured out what was really happening.

I live in the California desert, where triple digit temperatures, intense sun, rapid evaporation, and extremely hard fill water all have a major impact on pool chemistry. The problems I was fighting, rising stabilizer (CYA), heavy chlorine demand, and scale buildup, were not random. They were a direct result of my environment.

The pool store's advice did not account for that. Neither did the apps I tried.

Scale turned out to be one of the biggest challenges. Trying to understand why it kept forming led me down a rabbit hole into the Langelier Saturation Index (LSI), a calculation that predicts whether water is balanced, corrosive, or likely to form scale. It quickly became clear that LSI is one of the most important measurements for keeping pool water healthy, yet many apps either ignored it or oversimplified it.

I decided there had to be a better way.

What started as a spreadsheet eventually became PoolChem Tracker, a tool that tracks water chemistry over time, spots trends before they become expensive problems, and provides recommendations based on your actual pool, your climate, and the way pools behave in the real world, not generic averages.

Along the way, I also started writing

The same problem that pushed me to build the app also pushed me to start writing.

Good information about pool chemistry was scattered, contradictory, and often seemed more focused on selling chemicals than helping pool owners understand what was happening.

Questions like these kept coming up.

Why does high CYA make chlorine less effective?
What does LSI actually measure?
Why does pool store advice sometimes make things worse instead of better?

I answered those questions for myself first. Then I started publishing the explanations so other pool owners could benefit from what I had learned.

That is how this website grew alongside the app.

The calculators, guides, and explainers all came from the same place: a pool owner who needed answers and could not find them in one place.

Who it is for

Whether you are taking care of your first pool or you have owned one for years, PoolChem Tracker is designed to help you understand your water instead of constantly guessing.

If you just need to calculate how much chemical to add, the free calculators cover every common adjustment, including chlorine, muriatic acid, alkalinity, calcium hardness, CYA, salt, and LSI. No account and no app required.

If you want to understand the chemistry behind the numbers, the guides explain everything from chlorine basics to complete water balance in plain English for pool owners, not chemists.

And if you want to track your readings over time, spot trends before they become expensive problems, and receive recommendations tailored to your actual pool, that is exactly what the PoolChem Tracker app was built to do.

Many people discover the guides first and download the app later after realizing how much easier consistent tracking makes pool care.

Why privacy matters

Most pool apps require an account, sync your data to the cloud, or collect analytics about how the app is used.

I built PoolChem Tracker differently.

Your readings, dosing history, and pool settings stay on your device. The app works without an internet connection. There are no accounts to create, no cloud storage, and no analytics running in the background.

Your pool data belongs to you. It never leaves your device.

How the LSI calculator works

PoolChem Tracker calculates LSI from the measurements you actually test, including pH, calcium hardness, total alkalinity, water temperature, and total dissolved solids (TDS).

Some calculators let you adjust individual values until you reach a "perfect" LSI. That is not how LSI is intended to be used.

The correct approach is to test your water first, then calculate LSI from those real measurements. The Pool and Hot Tub Alliance has specifically warned against manipulating inputs simply to reach a desired LSI because doing so is inconsistent with the ANSI/APSP/ICC-11 water chemistry standard.

That is the approach PoolChem Tracker follows.

A note from the founder

I built PoolChem Tracker because it is the app I wish I had when I was learning how to take care of my own pool.

I am not a chemist, and I do not pretend to be one. Everything in PoolChem Tracker is built on established pool chemistry principles, industry standards, and years of maintaining my own pool while continually researching, testing, and improving the way I care for it.

Every feature exists because it solved a real problem I faced as a pool owner, not because I wanted the longest feature list.

I hope PoolChem Tracker helps make pool care a little simpler, a little more predictable, and a lot less frustrating.

Questions, feedback, or feature requests? I read every email: support@poolchemtracker.com

— Jeffrey Thompson, MBA