If your pool water doesn’t look right, it’s telling you something. Stains on the walls, foam sitting on the surface, or water that’s gone murky — these aren’t just cosmetic issues. Each one points to a specific problem in your water chemistry or filtration system, and the sooner you identify the cause, the cheaper and easier it is to fix. Here’s what the most common pool problems actually mean.
Cloudy or Murky Water
Cloudy water is the most common complaint we hear from pool owners across Limassol, Paphos, and Nicosia. It’s rarely one problem. It’s usually a combination of two or three things happening at once.
Low or Unstable Chlorine
If your free chlorine level drops too low, bacteria and algae begin to multiply faster than your sanitiser can handle them. In a Cyprus summer, this can happen in 24 to 48 hours. UV radiation here is intense from May through September, and it destroys unstabilised chlorine quickly. If you’re not using cyanuric acid (a chlorine stabiliser) or you’re running low on it, your chlorine is being burned off before it can do its job.
Poor Filtration
A filter that isn’t running long enough, or one that’s overdue for backwashing or cartridge cleaning, can’t clear fine particles from the water. During a dust storm — which Cyprus gets regularly, especially in spring when Saharan dust blows across the island — your pool can collect a significant amount of airborne debris in a single day. That fine particulate matter will cloud the water fast if filtration isn’t keeping up.
High pH or Calcium Hardness
Cyprus has hard water. The limestone geology across much of the island means tap water can have very high calcium content, often above 400 ppm in some areas. When calcium hardness and pH both climb, calcium carbonate comes out of solution and makes the water milky. This is sometimes mistaken for a chlorine problem, but adding more chlorine won’t fix it. You need to address the pH and total dissolved solids, and in some cases partially drain and refill the pool.
Foam on the Surface
A little foam that disappears quickly is usually nothing. Foam that sits, builds up, or comes back within an hour is a sign of contamination.
The most common cause is a high concentration of organic compounds in the water, typically from body oils, sunscreen, hair products, and sweat. In rental villas and holiday pools with heavy bather loads through summer, this builds up faster than people expect. Your chlorine is reacting with these organics and producing chloramines, which foam.
Low calcium hardness can also contribute to foaming, though this is less common in Cyprus given the naturally hard water supply. If you’ve recently diluted your pool significantly with a water delivery or a lot of rainfall, check your calcium levels.
The fix is usually a shock treatment combined with a non-chlorine oxidiser, followed by checking your stabiliser and sanitiser levels. If the foam persists after shocking, your pool may need a partial drain.
Pool Stains
Stains are specific, and identifying the colour tells you most of what you need to know.
Green, Brown, or Black Stains
These are almost always organic. Leaves, algae, and debris that sit on the plaster or liner leave tannin stains that range from green to dark brown or black. In Cyprus, pine needles and eucalyptus leaves are particularly problematic because they break down slowly and release stubborn compounds. Brushing them off the surface before they settle is always easier than removing the stain after. Established organic stains usually respond to localised chlorine treatment and brushing, but deep stains in plaster may need an acid wash.
Blue-Green or Teal Stains
This colour range points to copper. Copper gets into pool water through corroding fittings and heat exchangers, through certain algaecides that use copper sulphate, or through the water supply itself. Ionisers also release copper into the water. Once copper is in solution, a pH shift or chlorine spike can cause it to plate out onto pool surfaces as a teal or blue-green stain. A sequestering agent can help keep metals in suspension, but you need to identify and remove the source first.
Reddish-Brown or Orange Stains
Iron and manganese are the usual culprits here. Both are present in varying concentrations in Cyprus groundwater and in water delivered by truck to rural or hillside properties. When iron oxidises in chlorinated water, it deposits on walls and floors as a rust-coloured stain. A metal sequestrant added regularly can prevent this, but treating an existing stain requires a stain remover product and careful attention to pH during the process.
When to Call a Professional
Most pool problems get worse the longer they’re left. Cloudy water that isn’t addressed can turn into a full algae bloom within days in July or August. A copper stain ignored through one winter becomes significantly harder to remove by the following spring. And chasing the wrong fix — adding chemicals to address a symptom rather than the cause — wastes money and can push other parameters further out of balance.
If your water doesn’t clear within 48 hours of treatment, or if you’re seeing staining you can’t identify, get a proper water test done and have someone look at the pool. Guessing with chemicals is expensive.
We cover pools across Limassol, Paphos, Nicosia, Larnaca, and surrounding areas. If your pool has a problem you can’t get on top of, call us or send an email and we’ll take a look.