Specialist supplier of scientific water analysis, beverage and laboratory test equipment

Swimming Pools & Spas: Professional Water Quality Testing in South Africa

Written by Janice M on . Posted in Swimming Pools

Clean, hygienic pools are crucial for the well-being of users. The golden rule for water treatment is “as much as necessary and as little as possible”. Checking the water quality parameters will allow you to take corrective action where needed before health risks arrive.

Selectech supplies equipment and chemical reagents for professional water quality testing of swimming pools and spas. The German engineered Lovibond® range of water testing equipment and reagents measure the actual condition and quality of the water with maximum precision.

The products are backed by the expertise of Lovibond®’s 130+ year history in the market and fully guaranteed. Step-by-step instruction booklets make it easy for even a layman to use.

Some of our customers in South Africa, such as Forever Resorts, Municipalities, Virgin Active and various swimming pool advice centres, have been using these products for many years to test recreational water quality.

Do you know what the municipal by-laws for swimming pools and spa baths in South Africa are?

Safety of water:

  • The water must be free from floating, suspended or settled debris or swimming organisms and the wall, floor, access ladders or steps and gutters must be free from slime and algae;
  • The pH value of the water must be not less than 7 and not greater than 8;
  • Where chlorine based disinfectants are used, minimum free available chlorine residual of 0,5 mg/1 with a maximum free available chlorine residual of 3 mg/1 must be maintained
  • Where a disinfectant other than chlorine is used, the residual level must be equivalent in effect to the requirements of subsection (3).
  • The total viable bacteriological count of any sample submitted for analysis in accordance with the acceptable methods must not exceed 100 organisms per ml of water
  • Escherichia coli type 1 bacteria must not be present in any 100 ml of water

Do you know what the Duties of swimming pool keepers are?

Find out at joburg.org.za – Public Health by-laws (hint: see chapter 12)

Frequently Asked Question:
How are the different DPD tablets used?

DPD tablets measure Chlorine levels, the most common form of disinfectant in water. It is widely used in swimming pools, drinking water and industrial process water.

When using Chlorine to disinfect water, the aim is to kill off the germs (pathogens) and then to leave a small amount of active (free) Chlorine in the water. This remaining Chlorine is also known as the “residual Chlorine” and is important as it is available to disinfect further contamination of the water.

Combined (total) Chlorine is the sum of the free Chlorine available in the water to disinfect future germs and the Chlorine that had bound with other elements in the water.

It is vital to calculate the correct amount of Chlorine to be added – too much is negative to health and wastes money, too little can result in a high level of disease causing pathogens. The Chlorine demand can be determined by deducting the residual from the amount of Chlorine added.

Uses of DPD 1 – 4 Tablets:
  • DPD1 measures free (residual) Chlorine, the Chlorine available to kill bacteria
  • DPD2 measures Monochloramine, a less effective and less widely used disinfectant than Chlorine
  • DPD3 measures combined Chlorine, so add DPD3 to the same sample as DPD1 and you will be able to calculate the total Chlorine
  • DPD4 is used to measure total Chlorine only

DPD tablets can accurately measure Chlorine levels in the range of 0.001 mg / l to 10 mg /l. When a sample has a chlorine level that is higher than 10, the colour is bleached out of the Chlorine tablet – there is a quick show of pink colour and then the sample returns to its original colour. Dilutions can be done to determine high range Chlorine levels.

DPD reagents are produced on the basis of international standard methods and the ISO standard method. The chemicals are of a crystalline white nature. If a reagent (tablets or powder) is not white but has turned grey/brownish or purple in colour, it has deteriorated. The use of deteriorated products must be avoided as they will give false results.

Lovibond® DPD tablet reagents Lovibond® DPD powder sachets Lovibond® DPD powder dispenser
View specifications of Lovibond® DPD tablets

Are you interested in learning more about improving professional swimming pool or spa water quality?

Send us an email  with your contact details and we can post you a copy of the Lovibond® Swimming and Spa Pool Water Treatment Handbook, together with a Catalogue. (Please include the name of the book in your email.)

Lovibond® Swimming and Spa Pool Water Treatment Handbook

A practical, 50-page booklet that explains how to look after a professional swimming pool or spa.

Basic principles of water treatment are explained, including the effect of different chemicals. Learn how to get right balance of chemicals and maintain safe water quality.


Historical comments (6)

  • Michelle Levai


    I would like a copy of the Lovibond Swimming and Spa Pool Water Treatment Handbook. Thank you!

    • Janice M


      Hi, Sure, we will email you a copy. We can also post you a hard copy of the booklet if you send us your postal address.

  • Richard Friedman


    Please send me a copy of the handbook to

    R Friedman
    Moreson Wine Farm
    PO Box 114
    Franschhoek 7690

    • Janice M


      Sure, Richard. Please let us know if you do NOT receive it.

  • Debra Mann


    Please can you send me a copy of the handbook.
    Address is 57 Broadlands, meltham, Holmfirth. HD95QY ENGLAND

    • Janice M


      Hi Debra, unfortunately we can only send the booklet in South Africa. I will email you a PDF copy, though.

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