For businesses

Pool water testing log template

To print and pin up in the plant room. Free, no sign-up, no email.

Print on A4 landscape. When printing, the site header and footer disappear and only the sheet is left.

What it is and what it is for

This is a pool water testing log template, ready to print on A4. It records, day by day, pH, free chlorine, combined chlorine, temperature, the number of bathers and the products applied — the history that lets you treat causes instead of symptoms, and the proof that the pool was being maintained if a complaint, a claim or an inspection comes up. It matters most on pools in public or shared use: holiday rentals, condominiums, hotels. Free to use, including commercially.

Content reviewed in August 2026.

Pool water testing log

manutencaopiscinas.pt

Installation / address
Pool volume (m³)
Type of treatment
Person responsible for the log
Month / year

Date	Time	pH	Free Cl	Comb. Cl	Temp.	Bathers	Product and dose	Notes	Initials

Reference ranges

pH: 7.2 – 7.6 (ideal 7.2 – 7.4)
Free chlorine: 1 – 3 mg/L
Combined chlorine: as low as possible; watch above 0.5 mg/L
Total alkalinity: 80 – 120 mg/L
Calcium hardness: 200 – 400 mg/L
Cyanuric acid: 20 – 50 mg/L, never above 75

Working ranges for chlorine-treated pools. They are not legal values: on a pool in public use, the local health authority or municipal regulations may set tighter ranges, and it is those that belong on the sheet.

Free template by ManutençãoPiscinas · manutencaopiscinas.pt · Free to use, including commercially

How to use it

1Print two sheets a month and pin them up in the plant room, in a clipboard or a plastic wallet.
2Measure at the same time of day where you can. A series taken at consistent times is comparable; one taken at random times is not.
3Record the number of bathers. It is the column nobody fills in and the one that explains almost every swing.
4Do not correct the log. If a value was wrong, write the new measurement on a new line, with the time. A record with things crossed out loses value exactly when it is needed.
5File the sheet at the end of the month. Twelve sheets are a year of history and the file you hand to an insurer, a condominium board or a buyer.

Who it helps most

Holiday rentals and short-term lets, where the log is the only proof of the water's state during a past stay
Condominium administrators, who have to answer to the owners and the general meeting
Hotels and pools in public use, where daily measurement is the norm and the record gets asked for
Private owners who look after the pool themselves and want to understand why the pH climbs
Anyone selling a property with a pool who wants to show how it was maintained

See what we measure and record

The columns, and what goes in each

One line per measurement. If you measure twice in a day — which makes sense on a hotel pool in high season — use two lines.

Date	Day of the measurement. Without a date, the record is worthless.
Time	It matters more than it seems: chlorine behaves differently at 9am and at 6pm.
pH	To one decimal place. Always the first value to correct.
Free Cl	In mg/L. The disinfectant still available.
Comb. Cl	In mg/L. Chlorine already spent — the cause of the smell and the stinging eyes.
Temp.	In °C. Warmer water consumes disinfectant faster.
Bathers	How many people used the pool since the last measurement. The column that explains the swings.
Product and dose	What was applied and how much. Not "treatment carried out".
Notes	Water clarity, filter pressure, backwashing, faults.
Initials	Who took the reading. On an installation with several people, it is what makes the log traceable.

Frequently asked questions

The questions operators ask us before signing. If yours is not here, call us.

Yes. Free to use, including commercially, with no permission needed and no attribution required. It was made to be used.

It depends on bather load, not on volume. On a family pool, once or twice a week. On a holiday-rental pool in high season, weekly at a minimum and before every guest arrival. On a pool in public use, every day it is open.

No. They are complementary. This log documents the on-site measurements, which let you correct on the spot. Laboratory analysis verifies parameters that cannot be measured poolside and is issued by a third party. On a public-use installation, both are normally expected.

The practical test: at least as long as a complaint or a claim relating to that season could still arise. When in doubt, keep them longer — paper takes no space, and a missing record is always read against whoever was responsible.

This page is the digital version: fill it in on paper once printed, or use it as the column structure if you would rather keep the log in a spreadsheet. What matters is that the fields are the same and the date is always there.

That is exactly what we do under a maintenance contract: we measure, we apply the corrections and we hand over the written record of every visit without you having to ask. The first step is a technical visit to the site, which sets the maintenance plan and the proposal.

Or leave the record to us

Under a maintenance contract, every visit's record is issued in writing and dated. In Lisbon and on the South Bank.

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