Swimming Pool Dosing- Getting it Right!

Have you ever wondered why you sometimes come out of a swimming pool with itchy, sore eyes? A common misconception is that there is too much chlorine in the water. But there can be a number of reasons why pool water causes irritation, and too much chlorine isn’t one of them.

When you take a dip in the pool, you want to know that the water is going to be clean and safe. That’s why, if you’re responsible for maintaining a swimming pool, you know how to check and maintain dosing levels.

Why is dosing so important?

Pool water is constantly being polluted by dirt, leaves, pollen, human perspiration, makeup and fake tan etc. So, to prevent the growth of unwanted bacteria and algae, and the spread of organisms from person to person, dosing must be done correctly.

The water must be kept at the right PH and Free chlorine levels, chemicals must be used properly and safely.

How does water hardness affect pool water?

Depending on where you live, water hardness will differ. If you’re not sure whether you have soft water or hard water, you can contact your local water authority for more information.

If you have soft water, with a pH level below 7.0 it’s considered acidic and can corrode metals and pool surfaces.

Hard water, with a pH level higher than 7.0 is considered alkaline. If the water hardness is above a certain level and the pH above 7.6, calcium deposits will occur. Think of it like your kettle at home. If you have hard water then you get a build-up of white scale on the spout and inside the kettle. The same will happen to the metal ladders within your pool.

Check your pH levels

The pH level indicates the relative acidity or alkalinity of your pool water. pH is measured on a scale from 0 (strong acid) to 14 (strong alkaline) and pH neutral is 7. In pools, a slightly alkaline level between 7.2 & 7.6 is ideal because this range is the most comfortable to the human eye, provides optimum use of free chlorine and provides water that is not corrosive or scale forming.

pH level too low?

If pH levels fall too low (below 7) you will find:

• Water becomes acidic.
• Eyes and skin may become irritated in the water.
• Your heater element, pump impellor and other metal fittings on the pool could corrode.
• Stains appear on the pool wall from dissolved metals.
• A loss of alkalinity.
• Pool liner going wrinkly.

pH level too high?

If pH is too high (above 8), the following can happen:

• Chlorine becomes inefficient.
• Pool walls become discoloured and scale forms.
• Water becomes cloudy.
• Filter may become choked due to being overworked.
• Eyes and skin may become irritated in the water.

What chemicals do I need?

Ideally in a commercial setting your chemical levels should be controlled by an automated dosing unit, hand dosing of chemicals should be a last resort.

Chlorine – This is a definite. Without chlorine, you won’t be able to keep your pool clean. Free Chlorine levels should be maintained between 1-3 ppm and combined chlorine levels below 1ppm to ensure you have an effective disinfection system.

Soda Ash or sodium carbonate – This can be added to the pool if the pH level is too low.

Sodium bisulphate – This can be added to the pool if the pH level is too high.

Photometer or a comparator pool water test kit – OK, this isn’t a chemical but you’ll need one or the other to check the pH and Chlorine levels minimum three times a day.

How can JC Leisure Solutions help?

Looking after your pool and getting the dosing right doesn’t have to be a headache. We’re passionate about ensuring that your pool is kept clean, safe and well-maintained. Our pool maintenance services in London, Essex, and across the UK, can do just that.

Regular pool maintenance reduces the risk of repairs caused by corrosion or a build-up of minerals. We can build a planned pool maintenance programme to suit your individual requirements. Anything from weekly to annually, there is a programme to suit your needs and your budget.

We are always on hand to support your business. Call us on 01376 513246 for more information about our pool maintenance services.