Maintenance and Safety
This page briefly outlines certain requirements, which, if followed, will maximise your enjoyment, prevent problems and protect your investment. Select from the topics on the left menu.
Regular Pool/Spa Maintenance
Why Sanitise?
Pool/Spa water is easily contaminated with algae and bacteria from a variety of sources, including wind, top-up water, pets and users.
Untreated or improperly treated pool/spa water can be a health threat. Properly chemically balanced and sanitised water, on the other hand, will provide a healthy and visually appealing environment for you, your family and friends.
Controlling these influences is an ongoing requirement and involves chemically balancing the water to ensure it is neutral to users, the pool/spa itself, and the pool/spa equipment.
Regular testing and balancing of your water, sanitising the water to oxidise contaminants, and, filtering the water to remove the oxidised contaminants takes little time, and ensures that all is well with the pool/spa water.
The following sections deal with each of these requirements and form an easy maintenance program.
Water Balance
Your swimming pool/spa is a water container and the water it contains must be suitable for both:
- The users; and,
- The container
Balanced water means that its chemical demands are being met.
If the chemical levels are too low, the water will aggressively seek the chemicals and minerals it needs by attacking the pool/spa surface and equipment. This may lead to severe corrosion problems. At the other end of the scale, high chemical levels will precipitate from the water and form scale on the pool/spa surface and associated equipment etc.
Out of balance water can cause expensive damage to the pool/spa and may also inhibit the sanitising process.
In simple terms, a scientific water balance program suggests that the pool/spa owner should balance the following variables:
- pH
- Total Alkalinity
- Calcium Hardness
pH
pH is a measure of how acidic or alkaline the water is, and, the pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 are acidic, and, values above 7 are alkaline.
With pool water, we are seeking a pH balance suitable to the safe and healthy human use of the pool/spa, together with the sanitiser being used.
Topping up your pool/spa, rain, heavy bathing loads, and, chemical additions can all change the pH level of your pool/spa water.
pH must be kept within the Recommended Ranges, as if it is too high or too low, it may:
- Create swimmer discomfort (itchy skin, red eyes etc), and/or
- lnterfere with the sterilising action of your water sanitiser.
pH is the most important aspect of your pool/spa maintenance program.
The Effect of pH on Chlorine
Effective sanitising relies on pH values. Therefore, sanitiser and pH levels should be the measurements you check and adjust most often.
Regardless of the chlorine type or chlorination process you use, any pH drift above the "Recommended Range" (7.2 to 7.6 or 6.8 to 7.2 for fibreglass pools,) will inhibit the sanitising effect of your chlorine.
For example, a pH level of 8.2 would mean only about 16% of your chlorine would be available to sanitise the water, which means that you would have to add more than 5 times as much chlorine to achieve the same sanitising effect. When the pH is lower than 7.0, the chlorine becomes extremely active and is rapidly consumed
Total Alkalinity (TA)
This is the measure of bicarbonates, carbonaies and hydroxides in your water. The Operational Range is 60 to 200 parts per million (ppm).
Your NSPI Accredited Specialist will advise you of the Recommended Levels to suit your pool/spa and its environment.
Low TA will lead to erosion of the inner surface in concrete and painted pools/spas as the water takes the chemicals it needs from these surfaces.
Low levels will also cause the pH levels to be very unstable with small additions of chemicals resulting in major shifts in the pH values. This is sometimes known as "pH bounce".
Your Total Alkalinity (TA), can be changed in the following ways:
- Adding "buffer" (ie. bicarbonate of soda), which is used to RAISE the TA
- Adding "acid" to the water to lower pH, will also LOWER the TA
- Adding "Top-up" water may change the TA (depending on the quantity and the TA of the top-up water itself).
The Interconnection between pH and Total Alkalinity
From the last section, it can be seen that acids will lower both the pH and TA, as there is an interconnection between these two chemical components, and because of this, they need to be always adjusted together.
The levels you are seeking to maintain are:
- A pH of 7 .2 to 7 .6 (or 6.8 to 7.2 in a fibreglass pool), and
- A Total Alkalinity of about 100 ppm (or, as directed by your SPASA Member).
Let's have a look at the interconnection, and assume that the pH is OK but the TA is low.
To raise the level of the TA, you must add, "Buffer" (Sodium Bicarbonate) at the required rate. However, "Buffer" is an alkali, and will also raise the pH, and "Acid" (used to lower pH), also lowers TA.
The idea is to raise the TA artificially high, so that when the "acid" is added (to lower the pH to the recommended range), the TA is also reduced.
Remember - do not try to do it all in one go - allow 6 to 8 hours between adjustments, testing each time.
Two "acid" types are used to lower pH. One is Hydrochloric Acid (Spirits of Salts), and the other is Sodium Bisulphate. Both of which will effectively lower the pH and TA.
Check with your NSPI Accredited Specialist as to which type is most suitable for you and your pool/spa. lf using Hydrochloric Acid to lower the pH, it is vital that it be diluted (one part of acid to ten parts of water), prior to adding to the water.
Note that the filter should be running during these additions, and, for about one hour afterwards to ensure adequate mixing.
No other type of "acid" should ever be used for pH or TA adjustments.
Calcium Hardness
In simple terms, measures the amount of dissolved calcium in your pool/spa water. The desired range is 80 to 500 ppm; however, you should consult with your NSPI Accredited Specialist for the specific requirements of your particular pool/spa finish, water supply, environment and equipment.
Both Total Alkalinity and Calcium Hardness need to be brought into balance, if not:
- Low levels will mean that the water is corrosive to the pool and or equipment, and
- High levels will lead to scale formation on the pool and equipment
A normal water test kit cannot perform measurement of Calcium Hardness, and we would suggest that a water sample be taken each month to an NSPI Accredited Specialist for testing. A rough rule of thumb in areas where calcium levels are not naturally high is that testing annually will suffice after the initial adjustment.
The only exception to this is; if you use Calcium Hypochlorite (65% Chlorine) to sanitise your water, and, depending upon the method used -this chemical can quickly raise Calcium Hardness levels, and may require more frequent testing and adjustment.
Sanitiser
Chlorine is the most commonly used water sanitiser in the world, and, there are many forms of this highly effective product, including:
- Granular Chlorine (calcium hypochlorite -65% active)
- Liquid Chlorine (sodium hypochlorite -10/15% active)
- Stabilised Chlorine (in two forms):
- "Dichlor" granular chlorine (approx. 60% active), and
- "Trichlor" slow dissolving tablets (approx. 90% active), also
- Salt Water Chlorinators (electronic units which produce chlodne by the electrolysis of salt in the pool water)
Whatever form of chlorination you use, for it to work efficiently, the pH must be within the Recommended Range. Queensland Health recommends chlorine levels be maintained at:
- At least one (1) part per million of Free Available Chlorine in an unstabilised pool/spa, or
- At least two (2) parts per million of Free Available Chlorine in a stabilised pool/spa.
Free Available Chlorine can be tested with a test kit.
Stabiliser
Ultra-violet light attacks chlorine, and "stabilising" the water involves adding the chemical CyanuricAcid, which reduces the amount of chlorine destroyed by sunlight. Up to 5 parts per million of free available chlorine can be destroyed in three hours of strong sunlight.
For health and financial reasons, it is important to overcome this effect as much as possible, and so stabilising the water is strongly recommended.
For the initial stabilising of a new pool/spa, Cyanuric Acid should be added to achieve the recommended level of 30 to 50 parts per million.
Stabiliser is lost through splash-outs and by backwashing the filter, and, will need to be replaced regularly, especially during the summer season. To do this, it is necessary to first test for the residual levels in the water.
NSPI Accredited Specialists can do this testing from a water sample, and, based on your pool/spa volume, can recommend how much stabiliser to add.
As you only need stabiliser occasionally, fix the correct level at the beginning of the summer season and then check it every few months during the year. Naturally, if you have to pump out water, or lose a lot through splash-outs or backwashing, more frequent testing and adjustments may be required.
Any Chemical Additions
As a general rule, you are far better off adding small amounts of chemicals whilst running the filter, and testing the effects after several hours. Attempting large chemical changes by adding large amounts of chemicals can result in big problems.