Describe the symptom
What changed? When did it change? Which pool, loop, or body of water is affected?
A repeatable workflow
Use the same three checks every time
A surprising test result is a reason to look closer. It is not an instruction to add a chemical. Use the same order at every site.
Make the reading trustworthy
Check the sample spot, reagent or meter, method, units, and timing before you act on a result.
Record what actually happened
Save the reading, site conditions, action, and follow-up result. Never turn a gap into a guess.
Start with the record
Choose a guide by the data you have
| If you have... | Start here |
|---|---|
| A low or falling free-chlorine result | Why free chlorine keeps dropping |
| A pH or total-alkalinity trend | Why pool pH keeps rising |
| A combined-chlorine result to investigate | What high combined chlorine means |
| A missed test or open gap in the record | What to do after a missed test |
| Timestamped readings between service visits | Automatic pool water testing |
| A log missing time, method, action, or follow-up | Digital pool chemical logs |
Choose a problem
Practical guides for recurring field questions
Each guide starts with the symptom. It shows what to check, what local rules may change, and what the test can—and cannot—tell you.
CHEMISTRY
Why free chlorine keeps dropping
Check the test first. Then look at sun, demand, flow, feeder output, pH, and stabilizer.
Read the chlorine guide → CHEMISTRYWhy pool pH keeps rising
Use pH and total alkalinity together. Check aeration, fill water, chemical type, and feed equipment.
Read the pH guide → CHEMISTRYWhat high combined chlorine means
Check the math and test. Then look at bather load, nitrogen, ventilation, and water flow.
Read the combined-chlorine guide → OPERATIONSWhat to do after a missed test
Record the gap. Test when the site procedure allows, then follow local escalation rules.
Read the missed-test guide → SYSTEMSAutomatic pool water testing
See what scheduled reagent tests can show between visits—and what they cannot replace.
Read the automation guide → RECORDSDigital pool chemical logs
Build records with the reading, time, source, action, and follow-up. A log cannot make a weak test valid.
Read the logging guide →Reference values are not automatically local requirements
The Model Aquatic Health Code (MAHC) is voluntary guidance, not federal law. Its reference values include pH 7.0–7.8, free chlorine minimums that change with cyanuric acid, combined chlorine above 0.4 parts per million (ppm) as an action concentration, and total alkalinity 60–180 ppm. These are guidance, not automatic local rules. The authority having jurisdiction (AHJ), adopted code, product label, and current site procedure control.
Where Amano fits
Automation adds visibility between visits
Amano runs scheduled liquid-reagent tests for free chlorine, combined chlorine, pH, and total alkalinity. It saves timestamped results and sends alerts after tests. This can help a service team spot a trend or a result that needs review between visits. It uses built-in cellular connectivity. It supports the operator; it does not replace required manual testing, inspections, product labels, site procedures, or judgment.
See Amano for service companies →Managing a commercial pool? See the commercial monitoring overview.
Sources and scope
Reviewed August 19, 2026. This hub is educational, not a substitute for the adopted code, AHJ direction, product labels, equipment instructions, or your company’s operating procedure.