GH levels refer to general hardness, which is sometimes referred to as calcium hardness.
This level should not be confused with KH level which is carbonate hardness.
General hardness is the measure of how hard your water is and how many dissolved minerals it contains. Hard water is often described as having an adequate amount of calcium, magnesium, and other essential minerals available.
Calcium is said to make up approximately two thirds of the general hardness of your pond and magnesium makes up roughly a third. Whereas soft water is described as having a distinct lack if these minerals which are essential for your livestock.
Gh levels are measured in German degrees (°dGH) or in parts per million (ppm).
The level should not decrease below and should ideally remain between 8°-12°dGH.
Your fish and other pond life such as plants require these dissolved minerals for growth and to maintain a balanced level of health. This is known as osmoregulation and assists the fish in regulating the amount of salt in the blood stream, it also helps the fish to regulate the amount of sodium and potassium loss through excrement.
A lack of these minerals is caused by your water being ‘soft,’ this reduces the amount of minerals available. The unavailability of these minerals can lead to:
In order to ensure that these minerals are maintained and available there are a few things that can help:
