Cyprus summers are brutal on pool water. Between June and September, temperatures regularly exceed 35°C, UV radiation is intense, and humidity along the coast stays low enough to accelerate evaporation faster than most pool owners expect. A pool in Limassol or Paphos can lose 5 to 8 centimetres of water per week during a peak heatwave, sometimes more if there’s wind. That’s not a leak. That’s physics. But it still costs you money, disrupts your water chemistry, and puts extra strain on your filtration system if you don’t manage it properly.
How Much Water Are You Actually Losing?
Before you call a plumber, do the bucket test. Fill a bucket with pool water to about 2–3 cm from the top, mark the level inside and outside the bucket, and leave it on a pool step for 24 hours. If the pool drops more than the bucket, you may have a leak. If they drop by the same amount, evaporation is your culprit.
During a serious heatwave, evaporation alone can account for 3 to 5 mm of water loss per day. Over a week, that adds up to 20–35 mm, which translates to several hundred litres for a standard private pool. For villa owners with larger pools, that figure climbs significantly.
Wind makes this worse. Properties in elevated areas around Limassol or Paphos Hills that catch the prevailing summer winds can see evaporation rates nearly double compared to sheltered gardens at sea level. Dust-laden winds from the Sahara, which arrive in Cyprus several times per summer, can also deposit a fine layer of sediment on the water surface, affecting evaporation dynamics and fouling the water at the same time.
The Chemistry Knock-On Effect
Water evaporates. The minerals, salts, and chemicals in that water do not. Every time you top up the pool, you’re adding fresh water to a solution that’s already becoming more concentrated. In Cyprus, this matters more than it does in northern Europe because the tap water is hard, typically between 300 and 500 mg/l of calcium carbonate depending on your local supply and whether your water comes from a desalination plant or a reservoir.
As evaporation concentrates the existing water and topping up adds fresh hardness, calcium levels creep up over time. Scale starts forming on the waterline tiles, on heat exchanger surfaces, and inside the pipework. Chlorine becomes less effective at higher calcium hardness, so you may find yourself using more sanitiser just to maintain the same protection. Total dissolved solids also rise, which can leave the water looking flat or slightly cloudy even when the chemistry readings look acceptable on paper.
Monitoring your water regularly through summer is essential, not optional. During a heatwave, test every 3 to 4 days rather than weekly. Pay attention to calcium hardness, total alkalinity, and pH, all of which drift upward as evaporation strips water from the pool faster than you’re replacing it.
Practical Ways to Reduce Evaporation
Use a Pool Cover
A good quality solar cover (also called a bubble cover or thermal blanket) is the single most effective tool for reducing evaporation. Studies consistently show that covering a pool when it’s not in use reduces evaporation by 90% or more. In Cyprus, this translates to a real and measurable saving on water bills, chemicals, and topping-up frequency.
Solar covers also help maintain water temperature overnight, which is useful if you’re running a heat pump. The downside is that during extreme heat, they can raise daytime water temperature beyond a comfortable swimming range, so most owners use them at night or during periods when the pool isn’t being used.
Automatic safety covers and slatted covers are a more expensive option but significantly easier to use day-to-day, which means they actually get used rather than sitting rolled up beside the pool.
Shade and Wind Reduction
Structures that provide shade — pergolas, sail shades, natural tree cover — reduce direct solar radiation on the water surface and lower evaporation rates. Wind is often underestimated as a factor. A pool in an exposed garden loses noticeably more water than one surrounded by walls or mature hedging. If you’re landscaping or building, it’s worth thinking about windbreak planting on the prevailing wind side.
Run the Pump at the Right Times
Running your circulation pump during the cooler parts of the day, typically early morning and evening, reduces the amount of water being agitated and splashed at the surface during peak evaporation hours. This won’t eliminate the problem, but it’s a simple adjustment that costs nothing.
When to Call a Professional
If you’re losing more water than the bucket test suggests evaporation can account for, or if your water chemistry is swinging wildly despite regular top-ups, it’s worth having someone look properly at your system. Leaks at the skimmer housing, around light fittings, or in underground pipework can masquerade as evaporation, and Cyprus’s limestone geology can cause ground movement that stresses pipe joints over time.
A professional water analysis is also worthwhile if your pool is approaching the end of summer and you’re seeing heavy scale deposits or persistent cloudiness. At that point, you may need a partial drain and refill to bring the total dissolved solids back to an acceptable level, something worth doing before the water gets any more concentrated.
If you’re managing a holiday rental property and the pool needs to stay in good condition for guests throughout the season, consistent professional monitoring is genuinely the most cost-effective approach. Chemistry problems caught early cost far less to fix than problems left to compound through August.
If you’re dealing with evaporation issues, water chemistry problems, or you’re simply not sure whether that water loss is a leak or just the Cyprus summer doing what it does, get in touch with us. We cover Limassol, Paphos, Nicosia, Larnaca, and surrounding areas. Call us or send an email and we’ll come and take a look.