Forecast vs. log

A pool app that predicts, not just records

Most pool apps are logbooks with a dose calculator: they remember what your water did and tell you what to add today. Pool Predictor Pro is a pool chemistry forecast. It works out what your water is going to do next, and when you need to act.

The difference, side by side

Logging is useful, and Pool Predictor Pro does it too. The forecast is what it adds on top.

A typical pool logging appPool Predictor Pro
What you seeToday's readings and your historyToday's readings plus every parameter projected days ahead, each with a confidence range
When to test nextYour call, or a fixed weekly reminderA next-check date, set by when the forecast says a reading could reach the edge of its range
"Will chlorine last the weekend?"You guessThe forecast shows the day free chlorine is expected to drop out of range
WeatherNot consideredYour local UV, temperature, rain, humidity and wind, day by day
Your pool's own behaviourGeneric rules of thumbLearns your pool's chlorine loss, pH rise, alkalinity, stabilizer and calcium drift from your tests
TreatmentsA record of what you addedEach dose moves the forecast, and slow-dissolving products (stabilizer, tabs, salt) ramp in over days instead of all at once
DosesToday's amount from a standard chartThe amount of the product you own, for your water's buffering, and only the remainder if a recent dose is still mixing in
A quick test of one or two readingsOther values go blank or resetCarries forward your last measured values and widens the uncertainty on them
Cover, salt cell, pumpUsually not modelledCover use, salt-cell output over time and pump runtime all feed the forecast

What a forecast tells you

Say you test on a Monday and everything is in range. A log stops there. The forecast keeps going: it runs your water forward a day at a time, through the sunny days and the rain in your local forecast, and shows each reading's likely path with a band around it for the uncertainty.

From that it gives you two dates. The next check is when the band reaches the edge of the healthy range, the point where a test is worth doing. The out-of-range date is when the central forecast itself crosses the line, the point where you need to act. Each comes with the dose that would fix it, in the product you use.

When you log the next test, the forecast restarts from the real numbers, and the gap between what it predicted and what you measured is how it learns your pool.

Pool Predictor Pro forecast screen: free chlorine predicted to rise above its range in one day, with the recommended fix

Why it matters

Honest limits

A forecast is a model, not a measurement, so the app shows how sure it is. The uncertainty band starts tight at your last test and widens with each day. When the next check comes from that uncertainty rather than a firm prediction, the app tells you to test first before you dose. Forecasts sharpen once it has several of your tests to learn from; the free tier's two tests aren't enough for that, so it uses industry-standard rates until then. Weather comes from your US ZIP code today; without a connection the app falls back to a seasonal estimate for your area.

Common questions

Can an app predict when my pool will need chlorine?

Yes. Pool Predictor Pro simulates your water day by day from your latest test, using your pool's profile, your local weather forecast and the products you've logged, and shows the day free chlorine is expected to leave its range. It also gives an earlier "next check" date, when the forecast is uncertain enough that a test is worthwhile.

How is Pool Predictor Pro different from other pool apps?

Most pool apps log your readings and calculate a dose for today. Pool Predictor Pro does that too, but its core is a forecast: every reading projected days ahead with a confidence range, a next-check date, and drift rates learned from your own pool's history rather than generic assumptions.

Does the forecast get more accurate over time?

Yes. With several tests it measures how fast your pool actually loses chlorine and how pH, alkalinity, stabilizer and calcium drift, after subtracting anything you logged as a treatment, and uses those rates. The prediction band narrows and the confidence score rises as it learns.

Do I need sensors or special hardware?

No. It works from any test kit or strips and your phone. There is no hardware to buy or replace.

Get it on Google Play

Try it free: one pool, two water tests and two treatment logs, no credit card. Or see all the features.