Introduction
"How much does it cost to maintain a pool per month?" is the question we get most often, and the honest answer starts by saying that it is not a question with a single answer — because whoever asks it is usually thinking only about chemicals, and chemicals are the smallest of the four components.
A pool's real cost has four components: chemicals, electricity, water and equipment wear. Three of them never appear on a bill with the word "pool" on it, and that is why most owners consistently underestimate the total.
This article takes the four components apart, gives you the method for calculating your own, and compares the result against the cost of a contract. For our current figures, see the price list.
Component 1: Chemicals
The only one most people count.
On an ordinary family pool on the South Bank, annual product consumption — disinfectant, pH corrector, algaecide, flocculant and testing consumables — typically runs at around €600 a year, with wide variation driven by three factors:
| Factor | Effect on chemical consumption |
|---|---|
| Pool volume | Proportional. An 80 m³ pool uses twice what a 40 m³ one does |
| Water temperature | Above 28 °C, chlorine degrades far faster |
| Sun exposure | With no cover, UV degradation is significant |
| Bather load | Every bather consumes disinfectant |
| Vegetation around | Organic matter consumes disinfectant and feeds algae |
| Dosing accuracy | Dosing by eye wastes between 20 and 40% |
That last point is the most actionable: whoever measures before dosing spends less than whoever doses out of habit. See Complete Guide to Testing Pool Water.
Component 2: Electricity
This is the component almost nobody calculates and frequently the largest.
The calculation is simple and worth doing with your own numbers:
Daily cost = pump power (kW) × hours running × price per kWh
An example, with a 0.75 kW pump running 8 hours a day:
0.75 × 8 = 6 kWh a day. Multiply by your kWh price and by the days in your season.
What changes this component drastically:
The filtration hours. Determined by turnover time (volume ÷ flow rate), not by habit. Many people filter less than they need — and have cloudy water — or far more than they need, and pay for it.
The pump. A variable-speed pump running more hours at low speed filters the same volume for a fraction of what a fixed-speed pump consumes. On a pool that filters many hours, this is the easiest component to reduce. See Variable-Speed Pumps.
Heating, if you have it. On a heated pool, heating becomes the largest component of all — and with no cover, most of that energy leaves through the surface by evaporation.
Component 3: Water
Evaporation is real and measurable. On an uncovered pool through an inland summer, with dry wind and full sun, the daily loss is significant — and every top-up is metered water.
Add to this the backwash water: every backwash uses tens to hundreds of litres, depending on the filter and the duration.
Two useful notes:
A cover substantially reduces evaporation. It is the same measure that reduces chemicals (less sun exposure), reduces electricity (less heat lost) and reduces the calcium hardness climb (fewer top-ups). One piece of equipment, four components.
Water disappearing fast may not be evaporation. Before assuming it is normal, compare against a reference: Pool Losing Water: Evaporation or a Leak?.
For those using well water this component is practically nil — in exchange for a different treatment plan, with a permanent metal sequestrant.
Component 4: Equipment Wear
The invisible component, and the one that produces the big bills.
Every component has a service life and therefore an implicit annual cost: the replacement price divided by the years it lasts.
| Component | Typical service life | Nature of the expense |
|---|---|---|
| Filter sand | 5 to 7 years | Predictable, plannable |
| Pump mechanical seal | 3 to 6 years | Predictable |
| Pump | 8 to 12 years | Predictable |
| Multiport valve | 10 to 15 years | Predictable |
| Lining | 15 to 30 years | Large, plannable long-term |
| Green-pool recovery | Unpredictable | €300 to €1,500, avoidable |
| Failure through poor maintenance | Unpredictable | €400 to €1,800, avoidable |
The last two rows are the important ones. The first five are the expenses of an organised owner. The last two are the price of there having been no plan — and they are precisely what makes the difference between an annual cost of €1,400 and one of €4,000.
💡 Dica Profissional
If you want your pool's real number, do this exercise once: note everything you spend on products over a year, calculate the pump's electricity with the formula above, count the water top-ups, and divide the cost of the replacements you made by twelve. The total usually surprises — and it is the only number worth comparing a contract against.
The Honest Comparison: On Your Own or Under Contract
Using current market figures, over one year, for a family pool:
| Without a contract | With an Essencial contract | |
|---|---|---|
| Chemicals | ~ €600 | Included |
| Trips to the shop | ~ €80 | Included |
| Algae or liner recovery | €300 to €1,500 | Included |
| Risk of equipment failure | €400 to €1,800 | Reduced |
| **Estimated annual total** | **€1,380 to €3,980** | **from €2,160** |
Two honest readings of this table:
If everything goes well, doing it yourself is cheaper. €1,380 against €2,160. That is true and not worth hiding.
The question is variance, not the average. The left column has a €2,600 spread between best and worst case. The right column is a fixed figure. What a contract buys is not a lower cost: it is a predictable one, without the month where the pump fails and the pool goes green at the same time.
Note too that electricity and water are in neither column — they are yours in both scenarios.
What Is Not Included in Either Scenario
To be complete: neither a maintenance contract nor treating the pool yourself covers works and replacements. Those are expenses of a different nature:
- Filter sand replacement
- Repairing or replacing the pump and equipment
- Repairing the lining or the structure
- Winterisation and opening, if not in the contract
- Recovering an abandoned pool
Mistakes That Increase the Cost
Not measuring before dosing. A direct 20 to 40% waste on chemicals.
Filtering by habit rather than by calculation. Either you overpay on electricity, or you have cloudy water.
Not covering the pool. The measure that simultaneously reduces chemicals, electricity and water.
Deferring the filter sand. A filter with dead sand forces more product for the same result.
Cutting maintenance in winter. The April recovery is the most expensive and most avoidable expense of all.
Heating without a cover. The energy leaves through the surface.
Frequently Asked Questions
How much does it cost to maintain a pool per month?
In chemicals, typically around €50 a month on an ordinary family pool. But the total cost includes electricity, water and equipment wear, and on that basis the realistic figure sits between €115 and €330 a month, depending on whether the year went well or badly. A maintenance contract starts at €180/month with a fortnightly visit.
What costs more: chemicals or electricity?
It depends on the filtration hours and the pump. On a pool filtering many hours with a fixed-speed pump, electricity is frequently the largest component. It is also the easiest to reduce.
Is a saltwater pool cheaper?
The chemicals are cheaper, yes. Against that there is the cost of the chlorinator cell, which has a limited service life and is expensive to replace, plus the cell's electricity consumption. Over ten years, the difference is smaller than it looks.
Is a contract worth it if I know how to look after the pool?
If you do, have the time every week and the pool is straightforward, doing it yourself is cheaper in a year when nothing goes wrong. A contract buys predictability and the disappearance of the table's two unpredictable lines.
How do I reduce the cost without reducing water quality?
In this order: a cover, a variable-speed pump, filtration hours calculated rather than estimated, and always measuring before dosing. We went into detail in How to Reduce Pool Maintenance Costs.
Why does a contract price vary so much between pools?
Because volume determines chemical consumption and filtration time, and visit frequency determines labour. Two pools with the same visit frequency can carry very different figures on volume alone.
Conclusion
A pool's cost is not what you spend at the chemicals shop. It is the sum of four components, and three of them do not have the word "pool" on the bill.
Key points to remember:
- Four components: chemicals, electricity, water, equipment wear.
- Electricity is frequently the largest, and the easiest to reduce.
- The two unpredictable lines — recovery and failure — are what separate €1,400 from €4,000.
- Doing it yourself is cheaper on average and far more variable.
- A cover reduces three of the four components at once.
If you want your pool's figure rather than an average, the on-site technical diagnosis measures volume, flow rate and equipment condition and hands you a written quote. It costs €45, deductible from your first month under contract.
