Types of pools and differences in maintenance

Not every pool is the same. The material of the pool shell, the lining, the circulation system and the method of disinfection determine how the pool is maintained, how sensitive it is to mistakes and which malfunctions are most common.

Concrete pools with ceramic tiles, mosaic or a final coating

Concrete pools are common in more luxurious properties and holiday homes because they allow great freedom of design. They can be rectangular, irregularly shaped, with a beach entry, steps, benches, an overflow edge or special effects.

Advantages of concrete pools

Disadvantages and maintenance particularities

With concrete pools, it is important to regularly brush the walls and steps, monitor limescale, check the joints and carefully balance the water. If the water is neglected, algae and deposits can attach to small pores and joints, so restoring the pool to ideal condition is slower than with smooth surfaces.

Pools with foil or liner

Pools with foil, or a PVC liner, are very common in private accommodation. The liner is a waterproof covering placed over the pool structure.

Advantages of pools with a liner

Disadvantages and risks

With pools with a liner, it is important to use equipment and robotic cleaners that are compatible with the liner. Chemicals should not be poured directly onto the bottom. Granules are usually dissolved beforehand or dosed according to the manufacturer’s instructions, and tablets should not be left lying on the liner.

Fibreglass, polyester and composite pools

Fibreglass and composite pools come as prefabricated shells or ready-made modules. They are often advertised as easier to maintain because they have a smooth surface.

Advantages

Disadvantages

These pools can be very practical for tourist accommodation, but they still require proper chemistry, filtration and regular checks. A smooth surface does not mean that the water can be maintained less frequently.

Natural and biological pools

Natural pools use plants, biofiltration and special zones for water regeneration. They can be very attractive aesthetically, but they are not always practical for classic tourist rental.

With guest accommodation, expectations should be managed carefully. A guest who books a pool often expects classic clear, disinfected blue water. A biological pool works according to a different logic and requires different communication, different maintenance and clear rules of use.

For most holiday homes with intensive use, a classic pool with controlled filtration and disinfection will be a simpler, more predictable and safer choice.

Skimmer and overflow pools

One of the important differences in maintenance is the way water is collected from the surface of the pool.

The water surface is the most heavily loaded part of the pool. Oils, sun creams, leaves, insects, pollen and other impurities collect there. That is why well-designed surface circulation is essential for clean water.

Skimmer pools

In a skimmer pool, water is drawn in through the skimmer, an opening in the pool wall. The water level is a few centimetres below the edge of the pool.

With skimmer pools, it is important to clean the skimmer baskets regularly, maintain the correct water level and properly direct the return jets. If the skimmer does not draw in surface water, impurities remain on the surface and place a greater burden on the water chemistry more quickly.

Overflow pools

In an overflow pool, water flows over the edge into a channel, then goes into a compensation tank and returns through the filtration system back into the pool. Visually, they are very attractive because the water is usually level with the edge.

An overflow pool can be an excellent choice for luxury villas, but it requires a more serious approach to maintenance. In addition to the water in the pool itself, it is necessary to check the overflow channels, grates, compensation tank, automatic water refill system and the operation of the sensors.

Skimmer or overflow pool, which is better for rental?

For most accommodation providers, a skimmer pool is a more practical and simpler solution. An overflow pool has a stronger visual effect, but it requires better installation, more frequent monitoring and a faster response in case of malfunctions.

Filtration and circulation: the heart of the pool

Pool water must circulate constantly. Without good circulation, there is no good water chemistry. Chlorine, salt electrolysis, pH regulation and all other products can only work if the water passes through the system and if impurities are removed from the pool.

Pool pump

The pump drives water circulation. It draws water from the pool through the skimmer, the bottom drain or the overflow tank, sends it through the filter and returns it back to the pool.

With the pump, you should monitor:

• whether there is any unusual noise;
• whether there is air in the transparent pump lid;
• whether the pump fills with water normally;
• whether water is leaking around the connections;
• whether the pump basket is clean;
• whether the pump runs at the scheduled times;
• whether the flow rate matches the size of the pool and the filter.

A pump that is too powerful is not always an advantage. It can create unnecessary consumption, put strain on the installation and reduce filtration efficiency if the flow rate is not matched to the filter.

Pool filter

The most common filters are sand, glass and cartridge filters.

How long should filtration run?

There is no single rule that applies to every pool. The pump running time depends on the pool volume, water temperature, number of bathers, type of filter, pump power, pool location, amount of impurities and method of disinfection.

During the tourist season, especially in July and August, filtration usually has to run significantly longer than in private use. With high temperatures, heated water and a large number of guests, saving on pump operation is often paid for later through cloudy water, higher chemical consumption and emergency interventions.

A practical rule is: the water must be in motion long enough for the entire pool volume to be processed several times, while the actual running time should be adjusted according to measurements and the condition of the water.

Pool water chemistry

Water chemistry is the most common source of pool problems. Water may look clean even though it is not chemically in good condition. Likewise, cloudy water is not always a sign of insufficient chlorine; sometimes the problem is pH, filtration, hardness, organic load, saturation with stabiliser or incorrect use of products.

pH value

The pH value shows whether the water is acidic, neutral or alkaline. In pools, pH is one of the most important parameters because it directly affects the effectiveness of chlorine, the comfort of bathers and the condition of the equipment.

In practice, pools often aim for approximately 7.2 to 7.6, depending on the system, type of disinfection and the equipment manufacturer’s recommendations.

pH-minus and pH-plus

pH-minus is used when the pH is too high. pH-plus is used when the pH is too low.

The most common mistake is adding pH correctors without measurement or adding too large an amount at once. pH must not be adjusted by guesswork. The water must be measured, the product dosed according to the pool volume, circulation allowed to run and the condition checked again.

Free, combined and total chlorine

When maintaining a pool, it is not enough to know only that there “is chlorine” in the water. It is important to distinguish between free chlorine, combined chlorine and total chlorine, because this difference often explains why the water smells, why it irritates the eyes or why it becomes cloudy even though the test shows the presence of chlorine.

How to read measurement results?

When people say that a pool smells strongly of chlorine, the problem is often not too much good, free chlorine, but the presence of combined chlorine and chloramines. This happens when chlorine is used up on sweat, urine, sun creams, organic impurities and dirt, while the water is not properly balanced or sufficiently oxidised.

That is why, with more serious maintenance, it is important to measure more than one value. pH, free chlorine, total chlorine and the condition of the filtration together provide a much clearer picture than simply saying that “chlorine has been added”.

Chlorine tablets, granules and multifunctional tablets

Tablets are useful, but they should not be the only method of maintenance. In a tourist pool with heavy use, additional pH adjustment, shock treatment, manual dosing or automatic regulation is often required.

Flocculant: what it is and why it should not be overused

A flocculant is a product that binds fine particles into larger clusters so that the filter can retain them more easily or so that they sink to the bottom and can be vacuumed up.

It is useful for slight cloudiness, particles that the filter has difficulty capturing, water recovery after a more serious problem and certain situations following a shock treatment.

Flocculant is not a magic solution for every case of cloudy water. Excessive use can cause additional cloudiness, sticky deposits, put strain on the filter and complicate cleaning. Particular care is needed with cartridge filters because some flocculants are not suitable for such systems.

Before using a flocculant, the basics should be checked: pH, chlorine, filtration, filter pressure and mechanical dirt.

Algaecide

Algaecide is used to help prevent or control algae, but it is not a substitute for chlorine, filtration and the correct pH.

The most common mistake is adding algaecide when the actual problem is poor pH or insufficient disinfection. If the water is green, the cause of the problem should first be identified: too little free chlorine, pH that is too high, poor filtration, a dirty filter, high phosphate levels or a high organic load.

Stabiliser and water saturation

A stabiliser, most commonly cyanuric acid, protects chlorine from breaking down quickly under the influence of sunlight. This is useful for outdoor pools, but only up to a certain point.

The problem arises when stabilised chlorine tablets or multifunctional tablets are used continuously and the water is not replaced often enough. The stabiliser accumulates. When there is too much of it, chlorine may be present in the test but less effective in practice. Owners then often add even more chlorine, which further worsens the saturation of the water.

In such a situation, the only proper solutio

Chlorination or salt electrolysis?

One of the most common decisions regarding a pool is the choice between traditional chlorination and salt electrolysis.

Traditional chlorine maintenance

With traditional chlorination, chlorine is added manually or through a dispenser. This may involve tablets, granules, liquid chlorine or a combination of products.

Traditional chlorination can be a very good solution, but only if there is regular monitoring and a good maintenance routine.

Salt electrolysis

With electrolysis, salt is added to the pool water, and the device produces chlorine through an electrolytic cell. The water is slightly salty, but far less than seawater. Guests often find such a system more pleasant because there is no strong smell, the water feels softer and disinfection is more stable when the system is properly adjusted.

Comparison: chlorine tablets and salt electrolysis

For tourist accommodation, salt electrolysis is often a very good solution, especially when combined with automatic pH regulation. However, it is not a substitute for maintenance. A saltwater system can also develop cloudy water, algae, excessively high pH, limescale, a clogged cell, insufficient free chlorine or a flow malfunction.

Robotic or manual pool cleaning?

Robotic pool cleaners have become almost standard for private pools and holiday homes. A good robot can make maintenance significantly easier, but it cannot replace a person.

A robotic cleaner cleans surfaces, but it does not maintain the water. A pool can have a perfectly clean bottom and chemically poor water.

When is manual cleaning necessary?

Manual cleaning is necessary during the initial cleaning before the season, after storms, following the appearance of algae, when removing sediment after using a flocculant, when cleaning the waterline, steps and benches, in corners that the robotic cleaner cannot reach, and when the robot is faulty or unsuitable for the type of pool.

Ideal maintenance combines a robotic cleaner, manual cleaning, proper filtration and chemical control.

Pool heating: realistic expectations

Pool heating is one of the important topics in holiday rentals. Guests often see the term heated pool and expect warm water regardless of the month, weather, bora wind, night-time temperatures and whether the cover is used.

What is a comfortable pool temperature?

For tourist accommodation, it is important to communicate realistic expectations to guests: a heated pool means that there is a system for warming the water, but it does not mean that hot tub temperatures can be guaranteed in all weather conditions.

Pool heat pumps

A heat pump is the most common method of heating a pool. It does not produce heat like a conventional electric heater, but transfers heat from the outside air to the pool water.

Spring and autumn do not have the same conditions

In spring, the days are getting longer and the sun is stronger, but the water is cold after winter. The pool, concrete, ground and the entire system start from a low initial temperature. The heat pump must first raise a large volume of water from a cold starting point.

In autumn, the water is often still warm from summer, but the days are shorter, the sun is weaker, the nights are longer and the differences between daytime and night-time temperatures are greater. The bora wind and cold night air can quickly lower the temperature of the water surface.

Pool cover: the most important part of heating

A pool cover is not an optional accessory, but a key part of the heating system. The greatest heat losses from a pool occur through the water surface, especially through evaporation. Without a cover, the heat pump often works only to compensate for what the pool loses during the night.

For rental accommodation, guests should be clearly informed that the cover must be used whenever the pool is not in use, especially overnight. If guests do not cover the pool, it will be more difficult to keep the temperature stable.

How to communicate pool heating to guests?

• the pool can be heated;
• the temperature depends on weather conditions;
• the cover must be used at night;
• during the early and late season, it is not realistic to expect hot tub temperatures;
• strong bora winds, cold nights and rain can lower the temperature;
• the usual goal is a comfortable pool temperature, not the temperature of a hot tub.

This type of communication reduces misunderstandings and complaints.

Jacuzzi, whirlpool and hot tub: why are they more sensitive than pools?

A jacuzzi is not a small pool. It is considerably more demanding to maintain because it has a smaller volume of water, a higher temperature, more jets and pipes, stronger water circulation, more aerosols, faster depletion of disinfectant, a greater risk of biofilm formation, faster changes in pH and a higher load per litre of water.

In a pool, impurities are diluted in a large volume of water. In a jacuzzi, just a few people can heavily burden the water within a short period of time.

Jacuzzi temperature

A jacuzzi usually operates at temperatures significantly higher than a pool. In practice, a range of around 36–38 °Cis often used for tourist accommodation, depending on the manufacturer’s recommendations, the season and the rules of use.

Jacuzzi disinfection

With a jacuzzi, it is especially important to measure the water more frequently than in a pool, clean the filter, replace the water regularly, rinse and disinfect the pipes, maintain the cover, prevent biofilm formation, avoid overloading the jacuzzi with too many users and clearly display the rules of use.

Legionella, Pseudomonas and hygiene

Hot tubs create fine droplets and steam that users may inhale. If the water is not maintained properly, the risk of microorganisms developing increases. For this reason, a jacuzzi in tourist accommodation should be treated more seriously than a pool. Warm water and jets create conditions in which a problem can develop quickly if maintenance is skipped.

The most common pool water problems

Cloudy water

Cloudy water is not always resolved by adding more chlorine. The basic parameters should be measured first.

Green water

Green water usually indicates algae. This occurs when disinfection is too weak, the pH is too high, filtration is poor or the pool has been neglected after a storm, hot weather or heavy use.

Resolving green water usually involves adjusting the pH value, carrying out a shock treatment, brushing the walls, increasing filtration, rinsing the filter, removing dead algae and checking the cause of the problem.

If the cause is not resolved, the algae will return.

Strong chlorine smell

A strong smell does not necessarily mean that there is too much chlorine. It often means that chloramines are forming because the water contains a high level of organic impurities or does not have enough free chlorine for proper disinfection.

The solution is not to add products at random. Free and total chlorine, pH, water load and filtration should be checked, and a properly controlled shock treatment may be required.

pH keeps rising

pH often rises with salt electrolysis, high alkalinity, intensive aeration, overflow pools, hot tubs, fresh water of a certain hardness and frequent topping up of water.

If the pH keeps drifting, alkalinity and the operation of the automatic dosing system should be checked instead of simply adding pH-minus repeatedly.

Limescale and white deposits

Limescale forms when the water has high hardness, a high pH, a high temperature or poor balance. It is more common in heated pools, hot tubs and areas with harder water.

It can appear on the waterline, ceramic tiles, electrolysis cell, jets, heat exchanger and pool cover.

Prevencija je uvijek bolja od sanacije: pravilan pH, kontrola tvrdoće, redovito čišćenje i sredstva protiv kamenca kada su potrebna.

Possible malfunctions and how to recognise them

In tourist accommodation, the speed of response is crucial. Guests will not wait several days for a problem to be resolved, and poor pool conditions are often immediately reflected in reviews.

Winterising the pool

Winterisation is the preparation of the pool for the period when it is not in use. Winters on Krk are not the same as in continental regions, but that does not mean the pool should be left without supervision. The bora wind, rain, leaves, temperature changes and occasional cold days can cause damage if the pool is not properly closed.

Basic winterisation steps

1. thorough cleaning of the pool;
2. vacuuming the bottom and brushing the walls;
3. balancing the pH value;
4. checking the chlorine level;
5. cleaning or backwashing the filter;
6. protecting the installations;
7. lowering the water level if required by the system;
8. adding a winterising product if necessary;
9. protecting the skimmer, jets and pipes;
10. switching off or protecting the equipment;
11. installing the cover;
12. periodic checks during the winter.

Not every pool needs to be drained. In fact, completely draining a pool can be risky for certain structures and linings. The liner, waterproofing, groundwater pressure and pool construction must all be taken into account. A pool should only be drained when there is a valid reason and when this is in accordance with the recommendations of the contractor or service technician.

Active and passive winterisation

For accommodation properties, it is advisable not to wait until spring before inspecting the pool for the first time. Winter checks can prevent expensive work in spring.

Seasonal pool maintenance plan

A change of guests and severe weather are critical points in pool maintenance. New guests perceive the pool as part of their first impression of the property, while a storm can bring more impurities into the pool in a single day than several days of normal use.

The most common mistakes made by pool owners