The chemical treatment of water consists in adding specific products to the water that keep it germ-free, perfectly clean and transparent, in compliance with current Swimming Pool Regulations.

Four steps must be followed for proper water treatment in public pools:

1. pH regulation

One of the factors that most affects the efficiency of disinfectants is the water’s pH level. It should be between 7.2 and 7.6 at all times.

Apart from keeping a pool in optimum working order, this range is ideal for bathers’ skin and eyes. If a pool’s pH is too low or too high, it reduces the effectiveness of disinfectants, which in turn leads to higher amounts of chemicals being used and increased maintenance costs, as well as posing a threat to the health of swimmers.

To keep the water in the above range, the pH must be tested daily using a chlorine and pH test kit that complies with standard UNE-ISO 17381 and liquid pH regulators added through dosing pumps.

CTX-15 (does NOT contain hydrochloric acid)

A pH reducer in liquid form for reducing the pH to between 7.2 and 7.6 when it is above 7.6. It is recommended for dosing with a pump.

Added value: It does not give off vapours that could irritate the skin and eyes of maintenance staff or corrode the metal parts of a pool.

CTX-25

A pH enhancer in liquid form for reducing the pH to between 7.2 and 7.6 when it is below 7.2. Recommended for dosing with a pump.

2. Disinfection

Pursuant to current Swimming Pool Regulations, pool water should be free of all organisms and pathogenic substances in quantities that could pose a risk to human health. Even if the water is clear and transparent, there will be micro-organisms in it that must be removed through proper disinfection.

The chemical treatment of water consists in using specific products so that water is kept germ-free, perfectly clean and transparent. In addition, the disinfectants used must have a residual effect in the pool wáter.

The most common methods for disinfecting water are:

Chlorine

Chlorine is highly effective in killing a wide range of pathogens that are usually found in pool water and it leaves residual levels behind that are easy to measure and control. It is cheap and is a disinfectant that has been successfully used in water treatment for many years.

Stabilised chlorine (trichloride/dichloride)

When trichloride tablets and dichloride granules dissolve, they produce a stabiliser that prevents the product from evaporating and the pool from running out of disinfectant quickly.

The use of trichloride tablets as a disinfectant ensures that there is the right level of residual chlorine in pools.

The level of free residual chlorine (water with disinfecting properties) should fall in the range of 0.5 to 2 ppm and is essential for destroying any microorganisms that may enter a pool once the water has been disinfected. To keep it in this range, the water should be tested daily for residual chlorine using a chlorine and pH test kit that complies with standard UNE-ISO 17381.

Less than 0.5 ppm of free residual chlorine will enable bacteria and algae to grow in the water, which results in unhygienic and unpleasant conditions.

In turn, it should be ensured that combined residual chlorine or chloramines (without disinfecting properties) be below or equal to 0.6 ppm. Should it rise above this level, a shock treatment should be performed to reduce or remove the chlorine (otherwise pools could be forced to close until the standard level is reached).

Chloramines form when free residual chlorine reacts with ammonia and nitrogenous waste from the biochemical breakdown of urea (basically from urine), proteins and amino acids introduced by bathers, ammonia from rainwater, and fertilisers and other chemical species introduced in the water.

They irritate the eyes and mucous membranes, and cause the typical smell of chlorine. Their disinfecting properties are also very low.

CTX-370 ClorLent 250 g (non-combustible)

Added value: Non-combustible products are safer to store, whilst retaining the same oxidising and disinfecting properties as combustible chlorinated products.

The exact amount of a chlorinated product required will depend on the number of swimmers, the sunlight and the temperature of the water, as well as atmospheric conditions in the case of outdoor pools. This product can be added by either placing the tablets in a pool’s skimmer baskets or by means of dosing systems (CLORIMAX), which can be controlled by automatic control and regulation systems.

NON-stabilised chlorine (DOES NOT CONTAIN CYANURIC ACID!):

Sodium and calcium hypochlorite are the cheapest source of a chlorinated disinfectant.

Chlorine is highly effective in killing a wide range of pathogens that are usually found in pool water and it leaves residual levels behind that are easy to measure and control. It is cheap and is a disinfectant that has been successfully used in water treatment for many years.

These products do NOT add cyanuric acid to the water, whose use is restricted by the Swimming Pool Regulations. The highest concentration allowed is ≤ 75 ppm.

The use of hypochlorites as a disinfectant ensures there is the right level of residual chlorine in pools.

The level of free residual chlorine (water with disinfecting properties) should fall in the range of 0.5 to 2 ppm and is essential for destroying any microorganisms that may enter a pool once the water has been disinfected. Less than 0.5 ppm of free residual chlorine will enable bacteria and algae to grow in the water, which results in unhygienic and unpleasant conditions.

The exact amount of a chlorinated product required will depend on the number of swimmers, the sunlight and the temperature of the water, as well as atmospheric conditions in the case of outdoor pools.

CTX-161 liquid chlorine

Sodium hypochlorite does not need to be dissolved as it acts immediately. It is added to the water using dosing pumps, which can be controlled by automatic control and regulation systems.

CTX-120 and CTX.121. Calcium hypochlorite with a 65–70% concentration of free chlorine in granules or 20 g tablets

Fast-dissolving calcium hypochlorite with a 65–70% concentration of free chlorine for disinfecting pool water, and keeping it crystalline and hygienically clean

This product should not come into contact with the surface of the shell in pools made of polyester, a liner or vinyl as it can cause their colours to fade. It can be added to the water by either placing the tablets in a pool’s skimmer baskets or, in the case of granules, by means of dosing systems, which can be controlled by automatic control and regulation systems.

Stabiliser

Product designed to prolong the disinfecting action of chlorine in pool water disinfected using hypochlorite (NON-stabilised chlorine).

CTX-400 ClorProtect

CTX-400 prevents the rapid breakdown of chlorine by the sun’s ultraviolet rays in pools treated with hypochlorite.

It can be added at the beginning of the swimming season in a pool’s skimmers or prefilter pump to keep the level of cyanuric acid in the water in a range of 30–75 ppm.

Bromine

Bromine is a powerful oxidant that is ideal for disinfecting pool water to the same degree of efficiency as chlorine. It is extremely effective against bacteria, viruses and fungi, in addition to removing organic impurities from the water. However, in contrast to chlorine it does not give off unpleasant smells or irritate the mucous membranes, and is extremely tolerant to increases in temperature and changes in pH, which makes it ideal for indoor pools, pools with heat pumps and spas.

Free residual bromine (water with disinfecting properties) should fall in the range of 2 to 5 ppm and is essential for destroying any microorganisms that may enter a pool once the water has been disinfected. To keep it in this range, the water should be tested daily for residual chlorine using a bromine and pH test kit that complies with standard UNE-ISO 17381.

CTX-130  20g Bromine

Bromine in slow-dissolving 20 g tablets for the continuous disinfection of pools and spas.

It does not give off unpleasant smells, nor does it irritate the mucous membranes. It also has a high tolerance to temperature and changes in pH.

The exact amount of a brominated product required will depend on the number of swimmers, the sunlight and the temperature of the water, as well as atmospheric conditions in the case of outdoor pools. This product should be added by means of dosing systems (CLORIMAX), which can be controlled by automatic control and regulation systems.

The most common methods for performing water shock treatments are:

Dichloride or fast-dissolving chlorine is ideal for use as a chlorine shock treatment.

Dichloride, better known as fast-dissolving chlorine, basically serves to recover water when its treatment has been neglected, or for times when many bathers have been swimming in a pool, or after a storm. It has been proved that it is highly effective.

ADVANTAGES:

– Easy to use and dose

– Fast-dissolving

– Neutral pH

– Stable against degradation due to the effects of UV radiation (sunlight)

– Requires little storage space

– Particularly recommended for liner, vinyl, polyester and painted pools

CTX-200-GR ClorShock 55 % Dichloride granules and CTX-250 ClorShock Premium Effervescent

fast-dissolving 20 g tablets of dichloride with 50% of active chlorine.

Due to its fast-dissolving action in water, the right quantity of residual chlorine is quickly obtained. It is more stable against the sun’s ultraviolet rays in comparison with other products. It does not alter the pH of water.

CTX-100-GR Oxipool

Activated oxygen in granules that are chlorine-free for shock treatments that destroy organic contaminants and for preventing the formation of chloramines. Pools can be used 15 minutes after the shock treatment has been performed!

The use of this product does not damage polyester or vinyl pools.

Prevention is better than cure!

Chloramines

Chloramines form when free residual chlorine reacts with ammonia and nitrogenous waste from the biochemical breakdown of urea (basically from urine), proteins and amino acids introduced by bathers, ammonia from rainwater, and fertilisers and other chemical species introduced in the water.

They irritate the eyes and mucous membranes, and cause the typical smell of chlorine. Their disinfecting properties are also very low.

It should be ensured that combined residual chlorine or chloramines (without disinfecting properties) be below or equal to 0.6 ppm. Should it rise above this level, a shock treatment should be performed to reduce or remove the chlorine (otherwise pools could be forced to close until the standard level is reached).

CTX-23 Cloramin Shock

A chlorine-free oxidising agent for shock treatments that destroy organic contaminants and chloramines.

Pools can be used 15 minutes after the shock treatment has been performed.

It is an ideal product for pools and spas treated with bromine, as Cloramin Shock converts inert bromine into active bromine, which goes on disinfecting the water.

3. Water clarification

Pool water often loses its transparency and becomes cloudy due to:

– Algae, bacteria and organic matter in the water.

– Precipitation of calcium and magnesium salts.

– Dust introduced by the air or bathers.

– Oxidation of iron and manganese salts.

– Mud in rainwater, etc.

In most cases, these particles that fall into the water are so small (colloidal) that they lack the sufficient size to be trapped by the filtration system.

Clarifiers or flocculants are products that help the filter and/or skimmer absorb the smallest particles by grouping them together, which makes them easier to remove. These products prevent cloudiness and the appearance of foam, as well as helping to eliminate any oils and creams floating on the water, which in turn keeps the filters running more efficiently.

Depending of the physical state of the water, they may be added:

-Directly on the water

Ensure the filtration system has been turned off and that there are no bathers in the water. Pour the amount of flocculant required in a recipient with water and spread this solution evenly across the water’s surface.

-In the skimmer

The amount of flocculant required should be placed in the skimmer in granule, tablet (1 to 3 per 100 m3) or cartridge form.
Injected in the circulation circuit

Using a dosing pump, 0.5 ml of flocculant should be injected for each m3 of running water at a point before the filter.

CTX-41 flocculant

A liquid polymer (polyaluminium chloride) whose great flocculating properties remove the colloidal particles that are found in pool water and cause cloudiness.

It is extremely efficient in very cloudy water. It improves the bacteriological quality of water and as a result reduces the consumption of products used for disinfection. It is particularly recommended for treating cloudy water and for continuous systems.

ADVANTAGES

Using flocculants will increase the size of the colloidal particles in suspension and they will settle on the pool floor, making them easy to remove.

Clarmatic

Automatic continuous flocculant dispenser for pool water (2l/h at 5 bar).

Ideal for: Public and private pools

Added value: The ideal device for forgetting all about adding flocculants to pools as it continuously injects the exact amount of flocculant required through a tube.

Recommended use: Add 5 ml per 10 m3 of flowing water. The tube should be regularly checked to ensure it is clean and that it works when the dosing pump connected to the Clarmatic unit is running (use water). Otherwise it should be cleaned.

CTX-40 flocculant

A solid flocculant (aluminium sulphate) whose great flocculating properties remove the colloidal particles that are found in pool water and cause cloudiness.

4. Algae prevention

Even when your pool is disinfected, algae growth can appear caused by chemical residues or external agents such as plants or trees around the pool, rain, sharp temperature changes, etc.

Algae are autotroph plant microorganisms that are carried into pool water by the air.

Autotrophs synthesise glucosides (organic matter) and release oxygen into the atmosphere thanks to the photosynthesis of carbon dioxide, light and mineral salts such as phosphates.

Types of algae:

– Green algae: These are the most common. They are fast-growing, are able to invade a swimming pool in 24 hours and they consume a great amount of chlorine.

– Yellow or mustard algae: They generally appear on the shady side of pools and are able to withstand 3 to 5 ppm of free chlorine.

– Black algae: They form black stains and have a layered structure in which the top layer protects the ones below, which makes them very difficult to eliminate. They are highly resistant to chlorine.

To avoid these problems, it is recommended that non-foaming products be used for the prevention and/removal of all types of algae that could appear in a pool.

The combined action of chlorine and algaecides is stronger than the separate use of chlorine and an algaecide (synergistic effect) in the same concentrations. Used at a concentration of 0.5 ppm, an algaecide acts as an algae inhibitor, but at concentrations of 1–2.5 ppm it acts as an algaecide.

CTX-530 AlgaStop Ultra

An extra strong, fast-acting algaecide with micro-flocculant properties that make it better able to eliminate algae that appear in water in suspension. It is non-foaming and compatible with most disinfectant treatments.

It reduces the consumption of chlorine and combats unpleasant smells. It can be used with any type of filter.

CTX-590 AlgaStop plus (recovery)

A super-concentrated liquid algaecide for the elimination of all types of algae during water recovery treatments in pools. It eliminates algae that are not otherwise eradicated using traditional algaecides.

5. Cleaning – Pool shell and filter care

Filters

A liquid descaler for cleaning the inside of filters. A liquid, acid-based descaler that removes limescale caused by salts in the water and dirt deposited inside sand filters.

CTX-57 Netafilter liquid filter descaler

A liquid descaler for cleaning the inside of filters.

A liquid, acid-based descaler that removes limescale caused by salts in the water and dirt deposited inside sand filters.

It is suitable for stainless steel and polyester filters whose filter bed is silex, sand or ecoglass.

Added value: A liquid descaler that does not release any fumes that are harmful to users or produce foam.

Pool shells

CTX- 51 WallCleaner

A cleaning detergent specially designed for removing limescale, organic waste and mineral deposits that form over time and stick to pool surfaces.

CTX-75 Waterline descaler

A specially formulated alkaline cleaning liquid for removing scum and dirt from pool edges and walls, and areas around them that may require cleaning.

Recommended use: Apply the undiluted product to a cloth or sponge and rub across the areas to be cleaned. In the case of persistent stains on surfaces near the waterline, it is advisable to lower the water level so that the product is able to thoroughly clean them off.

CTX-606 stainless steel cleaner

Product specially formulated for cleaning any stainless steel surface. It looks after, enhances and brings back the shine to stainless steel, as well as removing limescale, organic waste and mineral deposits that have formed over time and adhered to stainless steel surfaces.

SANITISERS

Cleaning products, sanitisers and air fresheners for sports facilities and gyms, perfect for keeping damp areas in changing rooms, showers and the areas around pools scrupulously clean.

CTX-70 Surfosan and CTX-74 Surfosan Ultra

Super concentrated sanitiser with a pleasant smell of pine made up of a mixture of various antiseptics and a neutral medium.

Ideal for: Any surface in sports and leisure facilities, as well as showers, changing rooms, pool copings and floors in general.

Sanitiser formulated to prevent the transmission of infections that can arise from the contact of skin with damp, contaminated surfaces.