Help & Advice

You can find in this section technical support guides and information to help you get the best out of your pool or spa. Read our Help & Advice here


Troubleshooting problems in swimming pools and spas. Read our FAQs here

Fast Delivery

Delivery is FREE for all orders over the value of £75.00 and £10.99 for orders under this value to mainland UK. Read more about our delivery policy here

Pool Size Calculator

Knowing your pool's volume is vital when making adjustments as all calculations and dose rates are based on it.

View Pool Calculator

Excellent Reviews

See what our great customers are saying about us on Truspilot.

View Reviews

PoolLab 1.0 Photometer Alkalinity M - 50 Tablets

This Item
Product ID:
In stock
  • Alkalinity Test Tablets for PoolLab 1.0
View All Product Details Here
Swimming Pool Size Calculator

PoolLab 1.0 Photometer Alkalinity M - 50 Tablets

KS4,3 Acidity is also known as m-Alkalinity, Total Alkalinity, Hydrogen Carbonate Hardness, Acid Buffering Power, Temporary Hardness, … Alkalinity describes the ability of water to buffer the increase of ph value influencing chemicals (flocculants, disinfection media – e.g. chlorine products – lowering or raising pH). To provide a sufficient buffering effect, alkalinity should amount to at least 0.7 mol/m3 and/or mmol/l. This value represents the hydrogen carbonated materials dissolved in water. The buffering effect in the 4.2 – 8.2 pH range relies on a balance between hydrogen carbonate ions and carbon dioxide dissolved in water. Should chemicals that lower the pH value of water be added (acids), then the hydrogen carbonate ion combines with these to form carbonic acid (which in turn dissolves into carbon dioxide and water) and water. At a 4.3 pH value all hydrogen carbonate ions are depleted; thus the KS4,3 Acidity designation. Should in contrast chemicals be added that raise the pH value (bases), then hydrogen carbonate ions form again out of dissolved carbon dioxide and water. The modified relationship between dissolved carbon dioxide and hydrogen carbonate ions thus determines a new pH value. The buffering capacity of water becomes too low at alkalinities below 0.7 mmol/l, thus making it difficult to determine the pH value. In such cases small amounts of acids and bases will immediately and intensively change the pH value. Furthermore, water will have a corrosive effect on pipe mains. An alkalinity value which is too low can be increased through the addition of sodium hydrogen carbonate and/or sodium carbonate. When alkalinity values are high, however, the buffering effect is too large and large amounts of pH regulators are needed in order to achieve a change in pH. Additionally, when conditions are unfavorable (warming, pH > 8.2), calcium tends to precipitate because carbonate ions form out of hydrogen carbonate ions which in turn form water-insoluble compounds in the presence of calcium or magnesium (see Total Hardness). Alkalinity that is too high can be corrected through – at least partial – replacement of water. Because pH values above 8.2 will stop the equilibrium between hydrogen carbonate ions and carbonate ions, the alkalinity of the water must then (pH value over 8.2) be measured with the Alkalinity-P method.

Storage & Handling

  • Store in a cool, dry place away from oxidizing and reducing agents, strong acid, alkalis, solvents and organic materials. 
  • Do not mix with other chemicals. 
  • Always wear suitable gloves and eye protection when handling.

Use biocides safely. Always read the label and product information before use.

To write your own review, please, log in or register