Ospa Water Care Guide for private swimming pools and whirlpools

Transcription

1 Ospa Water Care Guide for private swimming pools and whirlpools

2 The pool water treatment system 2 When you bought your Ospa system, you took the first and most important step towards convenient and problem-free water treatment. However, whether your pool water always stays hygienic, crystal clear and inviting in the future will depend to a substancial degree on you. Even the very best technology and equipment, even if it is fully automatic, can only work effectively if it is serviced properly and operated using the correct chemicals and consumables. When we design our systems we do everything possible to make this easy for you. Nonetheless, it is necessary and wise to have the system inspected and wearing parts renewed by an Ospa Customer Service technician at least once a year. Like all machinery, your Ospa system will repay you for regular maintenance by giving years of dependable service. The following pages explain the most important aspect of water treatment in a simple and easy-to-follow way. It is well worth taking the time to read through each chapter carefully, along with the operating instructions that came with your individual system. What are the causes of impurites in swimming pool and whirlpool water? People using the pool introduce organic substances in the form of skin particles, sweat, saliva, cosmetics, hair etc. into the water. Outdoor pools are subjected to additional contamination due to their open air environment and are more susceptible to algae growth. Without a water treatment system, even an unused pool would provide ever more favourable conditions for germs and bacteria. Although we are constantly exposed to bacteria, our natural defence mechanisms are generally able to deal with a moderate level. And not all bacteria are pathogenic, i.e. disease causing. But where there are non-pathogenic bacteria,

3 The pool water treatment system 2 What are the causes of impurities swimming in pool and whirlpool water? Filtration 4 Disinfection, oxidation and 6 keeping the pool free of algae Redox potential 8 ph value 9 Acid capacity 10 (carbonate hardness) Total hardness 11 Cleaning the pool floor 12 other types of bacteria that can be harmful to humans can also emerge. Naturally, a swimming pool or whirlpool that is only used by the family is comparatively less vulnerable controllable, so to speak. But even here, a dependable, well maintained water treatment system is needed to prevent rapid deterioration of the water hygiene level a process that is exacerbated by the water temperature. Water treatment in private pools mainly consists of filtration, disinfection, oxidation, ph regulation, dilution (addition of fresh water), cleaning of the pool floor and heating. Optimum results will only be obtained if all these elements are working together in perfect harmony. The clarity of the water is not a sufficient guide to its hygienic condition. Clear water is not necessarily clean water. Adding fresh water 13 and changing the water What if the water used to fill the 15 pool contains high levels of iron or manganese? Water temperature 16 Water care and pool floor 17 cleaning products Short summary of the 18 most important points 3

4 Filtration Ospa monoblockfilter unit semi-automatic Ospa monoblockfilter unit automatic 4 The first thing that springs to mind when thinking about pool water treatment is the filter unit. Its task is to circulate the water while filtering out and collecting the dirt. The filter unit running time has a great influence on the quality of pool water. The length of any pauses in the operation of the filter unit are dictated soley by the pool water quality and the degree of pool use. It is a false economy to reduce the running time of the filter to a minimum. And it is important that the filter unit is running whenever people are in the pool. The filter running time should be set so that a volume equivalent to at least twice the pool capacity is circulated every day. The electricity costs for the filter unit are inconsiderable compared to the time and trouble that you will have to go to if you need to clean the pool more often because you have not allowed the filter unit sufficient running time. The filter unit acts as a rubbish bin for the water treatment system in that the filtered out dirt is collected there. And, like all rubbish bins, it needs to be emptied before it overflows! So it is important that the filter is regularly and thoroughly flushed. As well as flushing the collected dirt away, this will keep the filter material free and uncongested, and maintain it in fully functional condition. Whereas fully automatic filter units flush themselves without any operator input, semi-automatic filter units must be manually switched over to flush mode at least once a week for an uninterrupted period of 5 to 7 minutes. This must be done even if no one has been in the pool. Without good filtration and good filter flushing, effective pool water disinfection cannot be ensured. More on pool disinfection in the next chapter.

5 Ospa filter unit 16 Super Ospa filter unit 16 Ospa super filter unit automatic Ospa standardfilter unit Super Ospa standardfilter unit 5

6 Disinfection, oxidation and keeping the pool free of algae 6 For water treatment in public swimming pools and whirlpools, only tested and approved systems and methods that conform to the public pool hygiene regulations according to DIN can be used (in the Federal Republic of Germany only). These proven and effective systems and methods are also highly recomended for use in private pools. The Ospa Chlorozone Unit is the ideal solution for effective oxidative disinfection without using inerts. Using a small quantity of ozon, the water undergoes supplementary oxidation and reaches the optimum level of oxygen saturation. It is worth emphasising that this is a highly economical and easy to manage process. If the water is disinfected by means of the manual addition of a chlorine-containing product, we recommend the well-proven Ospa Hypochlorite CA. This is an easy to use solid chlorine preparation (in powder form) with a high active chlorine content. It dissolves fully leaving the water completely free of cloudiness. Although chlorine-free disinfection continues to be discussed, experience has shown us that chlorine is a highly effective means of meeting oxidation requirements. It not only neutralises organic compounds, it burns them up in the pool water. This helps prevent the formation in the pool of unhygienic deposits which would constitute a further nutrient base for bacteria and microorganisms. Unfortunately, chlorine has a reputation for causing the typical swimming pool chlorine smell and for stinging the eyes. But this is only the case if increased amounts of chlorine are being used to make up for inadequate filtration. In this situation, too many chloramines are formed, and it is these that actually cause the unpleasant chlorine smell. Chloramines are pool water impurities that, although they have been attacked by chlorine, have not been fully burned up. In fact, it is quite easy to understand how the filtration system has an effect on the disinfection process: Bad filtration allows an unecessarily large amount of organic contamination to remain in the water, which leads to higher chlorine consumption, which, in turn, leads to the need to add large quan-

7 When choosing a pool disinfection system, you need to consider the following: 1. The system must exert a disinfecting effect on the water in order to eliminate the transmission of disease-causing agents. Chlorine can do this! 2. The disinfecting effect on the water must be measurable. Chlorine is measurable! And it is easy to do, with the Ospa Water Analysis Set. 3. The disinfectant must be able to effectively eliminate, by oxidation, those organic impurities that cannot be removed by filtration. Chlorine not only has a disinfecting effect, it also has an oxidising effect! tities of chlorine to to keep chlorine content at the correct level of 0.3 to 0.6 mg/l. Unnecessarily large quantities of dirt and large quantities of chlorine together produce a large quantity of chloramines. An Ospa filter system will collect everything that it is possible to filter out. The desired chlorine content of between 0.3 and 0.6 mg/l can be maintained without using a lot of chlorine. Small quantities of dirt and small quantities of chlorine together produce a small quantity chloramines. produce any unpleasant effects when used in well-filtered pool water. To measure the free chlorine content of the water, we recommend the Ospa Water Analysis Set DPD. If using product type no , the total chlorine can also be determined. Bound chlorine is the difference between these two chlorine values. It is a measure of the proportion of the total chlorine that is currently bound by organic pool contaminants. Ideally, this value chould be kept under 0.2 mg/l. number of reliable analogue and digital display and control systems, e.g. the Ospa BlueControl. All that is then necessary is an occasional manual water analysis as a double check that the automatic system is maintaining the correct chlorine content. So, let s keep to the rule: Chlorine is not supposed to be a substitute for adequate filtration, it is a disinfectant. At the correct concentration we recommend 0.5 mg/l it does not It is particularly advantageous if the dosing of disinfectant takes place fully automatically (i.e. is controlled by an Ospa Chlorozone Unit or a chlorine dosing unit). Our range includes a 7

8 Redox potential 8 Redox potential is measured in millivolts. The term redox comes from the first syllables of the words reduction and oxidation. Organic impurities have a reducing effect and the inorganic substance chlorine has an oxidising effect. When we measure the redox potential of pool water, we determine the ratio of reducing to oxidising substances. This is an important indicator for judging the water quality. At a redox potential of 700 mv or more, certain bacteria will be killed within 30 seconds. At higher values, e.g. 750 mv, bacteria will be killed even faster, indicating an even better level of disinfection. In private swimming pools and whirlpools, the redox potential can be used to control an automatic chlorine dosing system. There are a number of reliable display and control systems in our range. It is well worth having such a system because they save a considerable amount of time and work while ensuring consistently optimal water quality. If you use redox potential to control the disinfectant dosing (e.g. with an Ospa Chlorozone Unit ), simply set the redox potential so that the Ospa Water Analysis Set always shows a free chlorine content of 0.5 mg/l. To Ospa BlueControl the multi-function display and control computer with touch screen operation of the entire pool water treatment system. determine the correct potential, you will need to take a measurement a day for a number of days immediately following commissioning of the pool. Before long, you will have found the redox setting that produces the correct chlorine content for your pool. Thereafter, you will only have to use the Ospa Water Analysis Set once a week to check that the automatic system is maintaining the correct chlorine content. As the redox potential and with it the water quality is also influenced to a large extent by the ph of the water, redox-controlled disinfection will only be effective if the dosing of ph increaser and reducer is also automatically controlled. For this reason, all our automatic display and control systems for private pools are equipped to control both ph and redox potential.

9 ph value The ph (from the Latin potentia hydrogenii) of the pool water is a measure of its acidity, alkalinity or neutrality. It is important in pool water treatment because it influences, among other things, the effectiveness of the disinfectant and the tolerability of the water by skin, eyes, and pool components and materials. For the skin, a ph of 5.5 would be ideal. But water with such a high level of acidity would not only cause exces-sive corrosion of metals, it would also sting the eyes tears have a ph of between 7.0 and 7.5. So, we need to find a compromise ph. At Ospa, we have developed reliable display and control systems which make this process easier. Depending on the composition of the water used to fill the pool, these systems will be set up to control an Ospa dosing unit for either Ospa ph decreaser solution or Ospa KH/pH increaser solution (and sometimes even both). Ask your Ospa expert adviser what we can offer to suit your individual pool installation. In order not to cause damage to materials, the ph needs to be 7.0 or higher. But higher than 7.6, is too high to be comfortably tolerated by the skin and it will reduce the effectiveness of the disinfectant, negatively affecting the speed at which bacteria are killed. Therefore, in order to be comfortable for the skin and the eyes, avoid corrosion, and ensure that bacteria are killed quickly enough, we recommend a ph of not lower than 7.0 and not higher than 7.6. The ph must be regularly measured at least once a week. If necessary, it can be adjusted by adding Ospa ph decreaser or Ospa KH/pH increaser. 9

10 Acid capacity (carbonate hardness) Carbonate hardness is the portion of calcium and magnesium that is bound to natural carbonic acid. It can easily be measured with the Ospa Water Analysis Set and should be maintained between 2 and 10 dh. If it drops below 2 dh, the water will no longer have sufficient acid capacity and corrosion can result. If it rises above 10 dh, the ph will tend to rise as carbonic acid escapes from the water due to heating or water movement. It is very important to adhere to the filter flushing intervals and times recommended in the filter operating instructions. In the majority of cases, the fresh water that is added during this process will prevent a sharp fall of the carbonate hardness. It is recommended that the carbonate hardness of very soft water, i.e. lower than 2 dh, is raised to within the above mentioned range by adding Ospa KH/pH increaser. The higher the carbonate hardness, the higher the ph will be. And, unless it is automatically controlled, action will then have to be taken to lower the ph. 10

11 Total hardness The acid capacity (carbonate hardness) described on the previous page concerned calcium and magnesium that is bound to carbonic acid. Calcium and magnesium that is bound to sulfate, nitrate or chloride is known as non-carbonate hardness. necessary to pre-treat the water used to fill the pool. If you are in a particularly hard water area, we will be pleased to advise you on how to do this. As opposed to carbonate hardness, which changes due to ph and temperature variations, non-carbonate hardness remains relatively constant. Total hardness is the carbonate hardness plus the non-carbonate hardness, i.e. sum of all the calcium and magnesium salts dissolved in the water. In most regions, the total hardness is between 5 dh (soft) and 25 dh (hard). If it is higher, it may be 11

12 Cleaning the pool floor Regular cleaning of the pool floor is essential in order to maintain hygienic conditions in the pool. Circulation and filtration of the water at the bottom of the pool will have no effect on deposits which have sunk and adhered to the floor. Under these deposits, bacteria can multiply freely in places that the disinfectant cannot reach. Therefore it is essential that the pool floor is regularly cleaned using a pool floor suction cleaner. At the latest, cleaning needs to be carried out when deposits become visible. Outdoor pools may need to be cleaned every day. Indoor pools should be cleaned once a week. 12

13 Adding fresh water and changing the water In public pools, at least 30 litres of fresh water is required per person using the pool per day. This is because certain dissolved substances cannot be eliminated and the addition of fresh water is the only way to keep their concentration at acceptable levels. Otherwise, increasing pool water concentation will lead to increased electrolytic conductivity, which, in turn, will lead to a greater risk of corrosion. Even if no one uses the pool, the chemistry of the water will still be constantly changing. Private pool owners, too, need to be aware of this. If the filter unit is regularly flushed as described in the operating instructions, this is usually enough to ensure that the necessary amount of fresh water is added as the pool water level is automatically topped up. How often the pool needs to be drained and refilled especially if due to the above mentioned increasing pool water concentration and changing chemistry depends to a great extent on how well the operating instructions have been followed. It may be necessary to refill an indoor pool once a year if flushing has not been carried out as recommended. Outdoor pools must be refilled every year, before the beginning of the new season. If cleaning products (detergents) are accidentally spilled into the pool you will have to drain, clean and thoroughly rinse out the pool and perhaps even renew the filter material. Therefore it is essential that you take utmost care when cleaning 13

14 the edge of the pool and the poolside walkway. Swimming pools should not be filled with softened water as the carbonate hardness of pool water tends to reduce in any case. If soft water were to be used, then a corrosion inhibitor would need to be added. The use of these substances, which consist mainly of phosphates, should be avoided as they impair the effectiveness of the pool disinfection. 14

15 What if the water used to fill the pool contains high levels of iron or manganese? If the water used to fill the pool has a significant iron or manganese content, it is a potential source of problems. The pool disinfectant causes metals dissolved in the water to oxidise. The first sign of oxidation is a yellowish, greenish or even brownish colouration. When large quanitites of metal is completely oxidised, brown or blackish brown precipitate will form in the pool. This process, known as flocculation, is accelerated by a high ph. Copper dissolved in the water can also cause a greenish colouration and a dark, almost black precipitate. It is not possible for us to give blanket advice on how to deal with this problem as each individual situation is different. The best course of action is to contact your Ospa expert adviser or our Mutlangen works for more information. In general, a flocculation agent is added to the pool water. After thorough mixing, the filter unit is switched off. Then, when precipitation has occurred, the pool floor is thoroughly cleaned using a suction cleaner. 15

16 Water temperature 16 The temperature at which the pool water is maintained depends largely on personal preference. In our opinion, bearing energy consumption in mind, the water temperature of an indoor pool should not be more than 30 C. The air temperature in the pool room needs to be 2 or 3 C higher than the water temperature, otherwise too much water will evaporate. Most people find an air temperature of more than 32 C uncomfortable. If your pool is covered with an Ospa roll-out swimming pool cover, you will be killing several birds with one stone: Covering the water surface will almost completely stop evaporation. This saves energy not only by preventing heat loss, but also due to the greatly reduced need to dehumidify the pool room. If you have an Ospa roll-out swimming pool cover, and no one is using the pool, the room temperature can be reduced to the same as the water temperature (or even a little lower) in order to reduce pool room heating requirements. And with the appropriate heating and dehumidifying systems (which includes a sufficiently high capacity dehumidifier), the heat pump principle can be used to increase the temperature of the pool room when the pool is in use, while, at the same time, preventing condensation. Whirlpools should not have a water temperature of more than 36 C. Clinical studies have shown that particularly if a long time is spent in the whirlpool higher temperatures can lead to circulation problems, even in people who do not normally suffer from them.

17 Water care and pool floor cleaning products Your control and dosing systems have been set up and adjusted to work with the active ingredient concentration found in our products. For this reason, we strongly recommend that you only use Ospa water care products. If you use other chemicals, it may result in operational problems and ineffective water treatment. Moreover, we will no longer be able to help you with dependable advice and accurate information if you use products that are not known to us and which might not have been properly tested. If unsuitable cleaning agents are used, even if only small amounts get into the pool water, it can result in a lasting impairment of the water treatment system. It is even possible that the filter material will be rendered unusable. And interaction between various additives can lead to problems that are difficult to solve. 17

18 Short summary of the most important points 18 If you pay careful attention to the following points you will have gone a long way towards ensuring that your pool water is always fresh and inviting. 1. The filter running time must be sufficient. The rule of thumb is to ensure that a volume equivalent to at least twice the pool capacity is circulated every day. Example: The pool has a water capacity of 50 m 3, the filter unit has a throughput rate of 10 m 3 /h. The filter running time needs to be at least 10 hours per day. The water treatment system must always be running when people are in the pool. 2. Filter flushing must be done at least once a week for at least 5 7 minutes non-stop. 3. All installed pre-sieves must be cleaned at regular intervals, which depend on the degree of soiling. 4. Chlorine levels should be kept at approx. 0.5 mg/l. 5. Ideally, the Ospa BlueControl Pilot should display a redox potential of 750 mv or higher. 6. The ph value should not drop below ph 7.0 and not rise above ph The acid capacity (carbonate hardness) of the pool water should not be less than 2 dh or more than 10 dh. If necessary, correct it with Ospa ph decreaser or Ospa KH/pH increaser. 8. The pool floor must be thoroughly cleaned at regular intervals at the latest when dirt becomes visible. 9. EAs a rule, topping the pool up after the weekly filter flush will be enough to ensure that sufficient fresh water is added (see point 2). If the pool is being unusually heavily used, add an addi-tional 30 litres of water per person per day.

19 10. Only use Ospa water care and cleaning products. We have tested and approved these products so that you can count on them. Cleaning fluids must not get into the pool water! 11. Automatic display and control systems for ph and redox potential are almost maintenance free. However, it is necessary to replace the electrodes at least once every three months, and to clean and recalibrate the unit according to the operating instructions. 12. As with cars and all other machinery, your pool systems need to be regularly serviced. You should arrange for an Ospa service technician to thoroughly check the entire installation at least once a year. If the necessary servicing and cleaning is not carried out, faults or system failure can result. 19

20 Your Ospa consultant: Your Ospa service technician: Technical and design changes may be executed without notice. Ospa-Schwimmbadtechnik Pauser GmbH & Co. KG Goethestraße 5 D Mutlangen Telefon: Fax: ospa@ospa.info 0089P