Keeping your pool water safe and healthy doesn’t have to be complicated. Even if your water looks crystal clear, it can still be unbalanced or unsafe. This guide explains the basics in easy terms so you know what to test, what to add, and why it matters.
The Two Big Goals of Pool Water Care
1. Sanitation (keeping it clean) Your pool needs protection from bacteria and germs. The most common sanitizer is chlorine, and it must be kept at the right level to do its job.
2. Balance (keeping it comfortable) Balanced water protects swimmers and your pool equipment. The most important factor is pH (how acidic or alkaline the water is). But alkalinity and calcium hardness also matter.
The Must-Know Chemicals
* Chlorine (sanitizer): Kills germs and bacteria. * pH Up (soda ash): Raises pH. * pH Down (dry acid): Lowers pH. * Stabilizer (cyanuric acid): Protects chlorine from the sun. * Algaecide: Helps prevent algae growth. * Clarifier/Flocculant: Helps clear cloudy water.
pH: The #1 Thing to Watch
* Ideal range: 7.2 – 7.6 * Why? This range feels comfortable on your skin and eyes, makes chlorine work best, and keeps equipment safe.
If pH is too low (acidic):
* Water stings eyes and skin. * Metal parts corrode. * Pool liner may wrinkle.
If pH is too high (alkaline):
* Water turns cloudy. * Scale builds up on walls and equipment. * Chlorine stops working effectively.
Total Alkalinity (TA): The pH Helper
Think of alkalinity as a “shock absorber” for your pH. Ideal range: 80 – 140 ppm If TA is too low: pH bounces up and down. If TA is too high: Water turns cloudy and pH is hard to adjust.
Calcium Hardness: Protecting Surfaces & Equipment
* Ideal level: At least 200 ppm * Too low: Water eats away at plaster, tile, and metal. * Too high: Scale builds up on walls, tile, and heaters. * To lower hardness: the only option is draining and refilling with fresh water.
How to Test Your Water
* Test often so small problems don’t turn into big ones. * Daily: Chlorine and pH * Weekly: Total Alkalinity * Monthly: Calcium Hardness Test options: * Strips: Fast and easy, but less accurate. * Liquid kits: Accurate, but take practice. * Tablet kits: Good balance of easy and reliable. * Tip: Many pool stores will test your water for free.
Calculate the volume of water in your pool
Now that you have your test results it is necessary to calculate the volume of your pool to determine the quantity of water treatment products your pool needs. It is better to calculate the pool volume in liters rather than gallons, as it is easier to calculate the quantity of product required in metric rather than imperial. TIP – If you know your pools volume in gallons multiply the number of gallons by 4.5 to give you an estimate of the volume in liters. I.e., 1,000-gallons is approximately 4,500-litres. 1,000-litres is the metric equivalent of 220-gallons. If you are unsure consult the manual supplied with the swimming pool. With the Total Alkalinity & Water hardness now at the correct level you should now test & maintain your pH level. All dosage rates are per 1000-litres of pool water. If your pH is too low (below 7.4): • Use pH Plus (soda ash) 10g per day (per 1000-litres) until the pH has increased to 7.4 If your pH is too high (Above 7.6): • Use pH Minus (dry acid) 10g per day (per 1000-litres) until the pH has decreased to 7.6 Now that the water balance is correct, we now need to look at sanitizing the pool water.
Why do I need to sanitize my pool?
Sanitization is necessary to disinfect the pool water to prevent the spread of disease organisms from person to person & prevent unwanted growth of bacteria & algae in the pool. Your pool is constantly being polluted by the environment, dirt, leaves, pollen, human perspiration, uria & cosmetics etc. are introduced daily.
Which sanitizer should I use for my pool?
If you look around a pool shop, you will see different types and methods of sanitizer for your pool. All sanitizing methods have their good points and all chemical treatments also have their drawbacks.
Saltwater Systems (An Alternative)
Salt has been used for many years in Europe, Australia and South Africa, it removes the need to add chlorine to a pool. Salt-water chlorination works by having an electrolytic cell break down the salt (Sodium Chloride) dissolved in the water in order to produce chlorine that acts as the sanitizer. The solution produced by the chlorinator does not lose its disinfection force as it can be generated as required and directly dosed into the swimming pool water. Some chlorinators are also available with pH regulators included removing the need to manually adjust the pH level. Is a salt chlorine generator worth it? A salt water system provides clear water, has a lower annual cost, has no chlorine smell, and is gentle on skin and eyes. Advantages: • Eliminates irritated & sore eyes and skin. • Doesn’t bleach hair or bathing suits. • Puts an end to the “traditional” chlorine taste & smell whilst bathing. • Set & Forget – Just activate the system and set the desired chlorine level. • Salt in its natural form is a solid and therefore will not leave the pool via evaporation, chlorines natural state is a gas and does leave the pool with evaporation. • The salt iodine also helps sun tanning.
Chlorine: The Workhorse
The commonly used disinfectant for swimming pools is chlorine. In its element form chlorine is a heavy greenish yellow gas that is so toxic it has been used as a weapon in chemical warfare. Because of the extremely high potential for injury or death from improper use of chlorine gas, a number of chlorine compounds have been formulated to provide chlorine in forms that can be handled and used safely by swimming pool operators. Chlorine is “used” and measured in two ways: Free Chlorine Residual Is the amount of chlorine in the pool that has not reacted with foreign substances other than water. It is the chlorine that is still available to disinfect pool water and oxidise organic substances. Free chlorine residual should be maintained between 1ppm and 3ppm. (2ppm is optimum) Combined Chlorine Is basically “used” chlorine, that has reacted with foreign substances other than water and is no longer available in its free state (i.e. to disinfect the water) Chlorine combined with ammonia produces chloramines which cause eye irritation and an objectionable chlorine odour. For this reason combined chlorine residual should be kept to a minimum, preferably below 0.2ppm. A common misconception when chlorine can be smelt around a pool is that there is too much chlorine in the pool; it is in fact that there is too much “used” chlorine in the pool and in fact more chlorine needs to be added to increase the free chlorine level. Chloramines can be totally eliminated by using a UV treatment – this will be discussed in detail later in this guide. The only way to remove chloramines without a UV treatment is to shock treat the pool,this is discussed later in this guide. Total Chlorine Residual Is the concentration of free chlorine & combined chlorine. To determine the combined chlorine level you need to test for free chlorine & total chlorine. Combined Chlorine = Total chlorine – Free Chlorine Shock Treatment / Super chlorination Regular use of the pool will increase the organic matter in the pool water that in turn will lower the efficiency of the sanitiser being used. A shock treatment will burn these organic materials out of the water and therefore allow the sanitiser to do its job properly. It may also become necessary to shock treat a pool if the water turns green due to an algae bloom (this is discussed in detail later in this guide). When you shock treat a pool you are looking to increase the level of sanitising / oxidising chemical by a minimum of 3 times the normal amount. For information on the best way to shock treat your pool consult your local pool shop Caution! Never mix any swimming pool water treatment products together. Each product must be added to the water separately. Always add granules to water, never add water to granules.
ALGEA CONTROL
Algae are microscopic single celled plant life that multiply very quickly. Algae will bloom & grow in swimming pools if nutrients are present and the free chlorine level is too low. Below are descriptions of the three most common algae problems in swimming pools: • Green Algae – The most common algae in pools, floats in the water and coats pool surfaces. Left unchecked green algae will very quickly turn the pool water pea green. • Mustard Algae – Settles on the pool walls and causes a slimy yellow film. • Black algae – Appears in “buds” or clumps attached to steps & other pool surfaces. Chemical Solutions: • Green Algae - is very susceptible to chemical treatment. Shock treat the pool with chlorine & keep the filter running, brush the pool walls and floor. Periodically check the chlorine level and maintain above 3ppm until the algae clears. Once cleared you can prevent the future build up by using an appropriate algaecide. • Mustard Algae – Is much more resistant to chemical treatment and clings more tightly to pool walls than green algae. Shock treat the pool and then thoroughly brush & vacuum the pool. Again, when cleared a suitable algaecide can be used to prevent future outbreaks. • Black Algae – Is very difficult to remove. It can be controlled to some extent by frequent shock treatment and thorough brushing & vacuuming. Black algae can usually be controlled with the use of strong algaecides and maintenance of relatively high free chlorine levels, but complete removal may require draining and cleaning the pool.
IS THERE AN EASIER WAY TO KILL ALGEA?
Yes – Ultra Violet (UV) Treatment UV destroys the waterborne organisms including green, single celled algae and bacteria that make the pool water appear murky and unattractive. It will ensure clear pool water even in the absence of chlorine. Short wave ultraviolet light has a photo oxidization effect that destroys chloramines & other toxic by-products of chlorine, without adding additional chemical products. Fitting a UV treatment to your pool will also kill all algae instantly when it is passed though the UV treatment plant but will not prevent algae and slime growth on the sides and surfaces of the pool. Advantages: • A more pleasant bathing environment with fewer chemicals present. • Dramatically reduced chemical dosing by up to 78%, and therefore reduced chemical costs. • Instantaneous disinfection with every pass though the UV. • Removes all Chloramines (“used” chlorine) • Less wastewater disposal. • Less backwashing of filters that can become time-consuming. • Offers a second disinfection process that gives increased control on the microorganisms difficult to control with chlorine. • Can be retrofitted to any pool. • Very simple to operate & install. • No disinfection by-products created by the UV. • No danger of over dosing. • Does not affect the pH level in any way. • Low initial purchase cost & low running costs.
FILTER AIDS AND TOTAL DISSOLVED SOLIDS (TDS)
After a pool has been in use for a full season dissolved, solids may begin to accumulate. These non-filterable solids include body wastes, suntan lotion, stabilizer, dirt, pollen etc., all of which are too small for your filter to remove by itself. Adding a UV treatment system will reduce the TDS in the pool every time the water is passed through the UV treatment plant. However, if you do not currently have a UV system installed then you can use Filter Aids (also known as flocculants or clarifiers). When added to water the filter aids basically “stick” the small non-filterable particles together to increase their size so that they are then large enough to be removed by the filter.
SAFETY TIPS FOR HANDLING POOL CHEMICALS
• Always read all label directions on all products prior to using and only use as directed. • Use a separate, clean plastic measuring cup for each chemical. • Use a clean non-contaminated bucket to mix the chemical into the water. • For chemicals that require pre-mixing with water, always add the chemical to the water and not the water to the chemical. • Never mix one chemical with another chemical prior to ·adding to the water. • Use a separate bucket for each chemical you mix into water and never mix more than one chemical into the water in any bucket. • Never add chemicals to the water when people are in the pool. • Be sure to only add one chemical to the pool at a time and allow time for each chemical to circulate before adding another. • There are chlorinated products that are not compatible when mixed. Never mix different types or brands of chlorine together. • Never mix chemicals together. • Do not use quantities in excess of the recommended dosage on the label. • After shock treating, you must wait until the free available chlorine residual is at the level recommended by the label instructions. • Do not use contents of unlabeled containers. • Keep all chemicals out of the reach of children. • Be sure to properly store and handle chemicals in accordance with label instructions. • Store chemicals in a clean, cool, dry location out of direct sunlight. • Containers should always be kept closed when not in use. • Properly dispose of all containers. Do not reuse empty chemical containers. • Wash your hands thoroughly after handling the chemicals.
