What is Carbonate Hardness?

The extent of carbonate and bicarbonate contained in a sample of water is the Carbonate Hardness value of that sample. Carbonate Hardness affects all aquaria, both salt and fresh.

It is called many names, according to the jargon of an industry or country of origin of the test kit, eg CARBONATE HARDNESS = ALKALINITY = kH (German) = ACID BINDING CAPACITY.

Stability of pH

The Carbonate Hardness of water is an important measurement, because the level of Carbonate Hardness is the basis for the value of the pH in a given sample of water.

A strong Carbonate Hardness reserve in water can mean a very stable pH and the bonus of an alternative supply of carbon dioxide for plants and algae if supply runs short in an aquarium. This applies equally for marine or freshwater aquaria.

Depletion of the Carbonate Hardness Reserve

Acids which form as a result of the breakdown of waste products by bacteria (via biological filtration) is the most common way the carbonate hardness reserve is depleted. In aquariums with little or no carbonate hardness the pH is very unstable and can drop very quickly to acid.

Raising Carbonate Harness

Aquasonic Carbonate Hardness Generator Powder is recommended for fresh or salt water applications. 5g will raise the Carbonate Hardness of 100L of water by 20ppm.

Directions for Use:

The test kit has a dual range, which measures in steps of 10ppm or 20ppm (ppm = parts per million)

To Test in 10ppm:

1. Rinse the clean test tube several times in the water to be tested.
2. Fill the test tube accurately to the 10mL mark.
3. Add 2 drops REAGENT 1 and swirl to mix. A blue colour forms.
4. Now add REAGENT 2 a drop at a time and swirl to mix. Keep count of the drops. As the end point is reached the test tube colour will change to green. Add 1 more drop to complete the change to yellow. Multiply the number of drops by 10 for the reading in ppm.

To Test in 20ppm:

1. Rinse the clean test tube several times in the water to be tested.
2. Fill the test tube accurately to the 5mL mark.
3. Add 1 drop of REAGENT 1 and swirl to mix. A blue colour forms.
4. Add REAGENT 2 a drop at a time and swirl to mix. Keep count of the drops. When the colour changes to yellow the end point is reached. Multiply the number of drops by 20 for a reading in ppm.

Note:

Place the test tube on the white background of the colour chart with the light behind you. The colour in the test tube is best viewed with the natural light.