Rainwater and carbonate hardness
Life insurance for your pond
Rainwater is basically distilled water without any minerals and unfortunately it is often also acidic. That’s why – unless you live in the desert - you really have to get to grips with this issue.
It’s a hard life for a pond: It is exposed to all weather conditions, it gets unwanted rainwater and it has to digest leaves, flower pollen and any particulate matter that enters.
Rainwater sounds positive at first for most of us. Clean free natural water. Putting aside the matter of air pollution, let’s take a look at the composition of rainwater. Rainwater is basically distilled water and therefore free of minerals. And that is exactly the problem. Tap and well water contain minerals, which are essential for the pond to function, whether it’s a garden or koi pond. They are the water’s life insurance with all the living organisms they contain. The minerals in question are called general hardness and carbonate hardness. Let us start with the carbonate hardness, the meaning of which is not always fully understood. It’s not that simple to explain it in an easily understandable way either. The minerals of the carbonate hardness have the property to bind acids and bases. During the course of the day the acidity in the pond water changes (decreases) and the pH value rises. At night the opposite happens (the acidity rises) and the pH value drops. That’s how the pH level fluctuates within certain limits.
The carbonate hardness makes sure that the fluctuations in the acidity don’t become too large. Chemists say that the carbonate hardness buffers the pH value, meaning that both the increase and the decrease is reduced, or buffered. When the carbonate hardness falls below certain values, this effect fails and the pH value as a measure for the acidity doesn’t buffer anymore. And because a pH fluctuation from 8 to 6 doesn’t mean twice as much but 100 times more acid in the water, this is, unfortunately, a dramatic situation for the pond dwellers. All this sounds more complicated than it really is. In a nutshell: add the essential minerals to your pond regularly with JBL StabiloPond Basis and thus “insure” your pond against rainfall and the problems caused by pH level fluctuations. If you want to see these pH fluctuations in black and white, just use a pH test to measure your pond water once at sunrise and once just AFTER sunset. Should your pH value deviate more than 2, urgent action is needed!
The second aspect is the general hardness (GH), in other words the magnesium and calcium content of the water. With very low GH values in your pond water the fish need to expend up to 30 % more energy to attain their mineral balance (salt/water balance)! By adding JBL StabiloPond Basis regularly to your water, you can increase the mineral content of your pond water (which can drop dramatically at any time as a result of rain water intrusion) and thus reduce the stress it creates for your fish.