Madrid's Decreto 99/2024 requires a routine water check at least twice a day and the results to be recorded "according to the model in Annex IV, or an equivalent one containing the same information". That record is what's known as the pool log book.
Two checks a day, recorded and on display
Does your community have to keep one?
| Type of pool | Routine checks and log |
|---|---|
| Community of more than 30 homes | Yes: checks twice a day, a log and a self-monitoring protocol. |
| Community of up to 30 homes | Exempt from these checks and from the self-monitoring protocol, unless the health authority requires them (arts. 16.3 and 18.4). |
| Hotels, gyms, sports centres… (public use) | Yes. |
| Pool at a single-family home | Doesn't apply. |
A small community being exempt from the checks doesn't mean the water can be in any state: the quality values are the same. Keeping a simple log, even when it isn't mandatory, is the best way to show the water is fine if there's ever a complaint or an inspection.
When to test
At least twice a day, in each pool:
- In the morning, before opening to users.
- Halfway through the opening hours.
If any reading is out of range, the maintenance staff must be told so they can correct it.
What to record
At the top of each sheet: the name of the facility, the pool and the disinfectant used. And in each row, the columns of the Annex IV model:
| Column | How to fill it in |
|---|---|
| Date and time | The real time of the test, not a fixed time. |
| pH | The measured value. Legal range: 7.2-8.0. |
| Disinfectant (mg/l) | Free chlorine (0.5-2.0) or, if bromine is used, total bromine (2-5). |
| Turbidity (NTU) | Maximum 5. It can be measured with kits meeting UNE-EN ISO 7027-1, which must be kept at the facility at all times (art. 17). |
| Transparency | Whether the bottom drain is clearly visible: yes/no. |
| Recirculation time (h) | The hours it takes for the whole pool volume to pass through the filter. |
| Water temperature (°C) | In heated pools, 24-30 °C. |
| Air temperature, relative humidity and CO₂ | For indoor pools (air quality). Outdoors, write "not applicable". |
| Other | Any other parameter that is tested. |
| Person | Who carried out the test. |
| Remarks | What was corrected and how, or any incident. |
The most common mistakes
- Filling it all in at the end of the day, or with the same values every day: it shows straight away.
- Recording an out-of-range value without noting what was done. That's what the remarks column is for.
- Taking the sample in the wrong place, for example next to a return inlet, where the water has just received product. We explain it in the RD 742/2013 guide.
- Keeping the log at the chairperson's home. The paperwork has to be at the pool, available to maintenance staff and inspectors (arts. 18 and 33).
Download the template
We've prepared a landscape A4 sheet with the columns of the Annex IV model and two rows per day (before opening and mid-session) for one week. Print it as many times as you need.
Frequently asked questions
Can the log be kept in a spreadsheet or an app?
The decree accepts the Annex IV model "or an equivalent one containing the same information". What matters is that all the data is there and that it can be shown at the pool when requested.
Who has to carry out the tests?
Whoever is in charge of water control: the lifeguard, the concierge or the maintenance staff. Each row records who did it.
My community has 25 homes. Do I have to keep it?
Communities of up to 30 homes are exempt from routine checks and the self-monitoring protocol, unless the health authority requires them. Even so, the water must meet the same values, and a simple log is the best proof.