KH Test Kit

The Colombo KH Test Kit contains all you need for accurate measurement of the KH level in ponds and both freshwater and saltwater aquariums. The Colombo KH Test Kit comes complete with test tube and liquid reagents to provide accurate results for 25 tests.

The KH is the so-called carbonate hardness or temporary hardness; in German Karbonathärte, abbreviated to KH. The KH is made up by forms of carbonic acid like bicarbonate and carbonate. The chemical balance between these substances leads to a stable pH and thus the adequate presence of these substances is essential for a stable pH; a stable pH in its turn is essential for the well-being of the fish. The KH is therefore often called the buffering capacity of the water. Especially in older aquaria and ponds, the pH and KH have a tendency to decrease, especially when there are no or little water changes. Hence, test the KH regularly and refresh 10% of the water weekly. An optimal pH-buffer in freshwater is obtained with a KH between 6 and 8°DH, in seawater with a KH between 8 and 12°DH. When the KH is above 12°DH, also the pH will be relatively high, and so you can lower both values in freshwater with Colombo pH-min. If the KH is lower than 6 or 8°DH, you can increase it with Colombo KH+.

Instructions For Use:
1. Take a water sample of 5ml.
2. Add 1 drop of KH-test fluid and mix. The sample should turn light-blue; when it turns yellow, the KH of the water is lower than 1°DH.
3. Add KH-test fluid drop by drop and mix each time, until the sample turns yellow.
4. The number of drops added to induce the colour change from blue to yellow, is equal to KH-value in °DH, so 2 drops = 2°DH, 3 drops = 3°DH and so on.