Automatic top-up and leak detection: how to go on holiday with a clear head

Here is the pool owner's paradox: the pool, the ultimate symbol of a holiday at home, becomes a source of anxiety the moment you have to be away for a few weeks in summer.

"What if the water level drops below the skimmers? The pump will suck in air, run dry and burn out. What if a fitting lets go in the plant room?"

Those fears are reasonable. A burnt-out filtration pump costs several hundred euros — never mind a pool that turns green while you are away. Fortunately, home automation now makes it possible to secure the water level completely.

📉 Why does the water level fall?

In summer, a falling pool level is normal. Two natural things cause it:

1. Evaporation: in strong heat and wind, an 8 × 4 m pool can lose one to two centimetres of water a day — nearly a hundred litres.
2. Swimming, and the splashing that goes with it: dives and children's games throw a fair amount of water out of the pool.

After a week of heatwave with nobody around, the water level can get dangerously close to the bottom of the skimmer opening.

🚫 The danger of a pump losing prime and running dry

The skimmer is the rectangular opening at the top of the wall that draws in surface water. The water should reach about halfway up it. If the level drops below the skimmer opening:

1. The filtration pump no longer draws water, but air.
2. The water circuit loses its prime.
3. The pump motor, normally cooled by the water passing through, overheats as it runs empty.
4. The mechanical seals melt, causing an internal leak and destroying the motor.

On top of the hardware damage, filtration stops and the water stagnates.

🚰 The answer: automatic level control

To avoid that disaster, the answer is to automate the supply of fresh water. Historically, mechanical floats were used — like a toilet cistern — but they tend to jam.

Modern automation takes a far more reliable and safer approach.

How it works (the PoolNexus approach)

1. The sensors (level switches): small contactless magnetic sensors sit in the skimmer or in the balance tank. They continuously report whether the water is at an adequate level, low (alert) or critical (emergency stop).
2. The solenoid valve: on the mains water inlet that fills the pool, you fit a motorised or electrically driven valve.
3. The control brain: the automation unit reads the sensors. If the level has been low for more than ten minutes — to avoid false triggers from waves — it tells the valve to open.
4. The safety timer: the valve stays open for a set time, say thirty minutes, to bring the level back up, then closes again.

🚨 Detecting major leaks, and active safety

A simple automatic top-up system carries one major risk: if you have a large leak in the pool, mains water will run continuously trying to compensate — and you will get an astronomical water bill at the end of the year.

An intelligent connected system like PoolNexus includes software anti-leak safeguards:

• Daily top-up limiter: if the system detects it has had to open the valve for more than X minutes in a day — abnormal compared with ordinary evaporation — it cuts the water supply, locks the system and sends you an urgent notification ("Abnormal top-up detected: suspected leak").
• Pump protection (dry running): if, despite topping up, the "very low level" sensor triggers — a sign the pool is emptying fast — the system cuts power to the filtration pump immediately to save it.

📱 A holiday under control, with reassuring notifications

Thanks to the smart-home app, you are no longer in the dark. Thousands of kilometres away, on your sun lounger, you can check the status: "Water level: OK".

If something goes wrong, you get a detailed push notification. You can then decide, with one swipe, to force the installation off and ask a neighbour to take a look — limiting both the hardware damage and the wasted water.

Conclusion

Automatic top-up coupled with software protection is the peace-of-mind investment par excellence for any pool owner. It protects your filtration equipment, keeps your water bill under control when a leak appears and, above all, gives you back the freedom to go on holiday with a genuinely clear head.