The Consequences Of Hard Water On Koi And Garden Fish Ponds...

Hard water is perfect for ponds as it creates a buffering effect and results in lower pH levels ideal for Koi and most garden pond fish ... see table below for "definitions" of hardness. The water in the pond should not be too hard ortoo softas this will have a negative impact on the garden water inhabitants. In a garden pond setup, Alkalinity is the common term used to describe water hardness.

Alkalinity can simply be defined as the measure of the concentration of alkaline materials in the pond water and the capacity of the water to accept any acidification without significantly affecting the pH (known as the buffering capacity and is vital for all garden ponds).

Alkalinity is normally measured as either mg/l (milligrams per litre) CaCO3 (Calcium Carbonate) -- see table below.

Alkaline ranges between 20 - 300mg/l are perfect for pond fish. Garden water with alkaline levels below 20mg/l is considered too soft and thus will have a very low buffering capability and thus pH will differ greatly.

If acids flow into the water in the garden pond, especially just after heavy rainfall( which is acidic), the end result will be a great reduction in the pH levels.

Such constant changes in the pH are dangerous for the fish as all fish thrive in a stable and non-stressful environment. Water that has low alkalinity can easily be treated using lime. Experienced pond keepers put shells inside filters to increase alkalinity. High alkalinity levels are not too good as well as they result in a fish nephrocalcinosis (a condition where the fish have high calcium concentrations in kidneys)

Pond keepers lower the hardness ofhard water by mixing in it with softened water ... and this can be done using the in-house water softener.

What is hard water?

Hard water is water that has excessive amounts of calcium and magnesium. Hard water is common in water that occurs in chalky countryside, in regions where limestone is present. Some rivers in England rivers are commonly known as chalk streams ... i.e. rivers that are not effected by rain and normally flow gently and smoothly. The water flowing into these streams is rainwater that infiltrates through calcium and magnesium rich structures.

Aquatic creatures adorehard water and trout grow very big when feeding in hard water.  The native Americans refer to chalk streams as Spring Creeks.

The majority of natural water supplies contain from around 3 grains per gallon (gpg) to 50 gpg (or 51 mg/l to 855 mg/l). These hard water substances in the rain leave a film scale) on any surface that come in contact with the water ... such as the bath tub, coffee cup and etc. Hard water stains in the sink are very common in areas with hard water.

Hard water results in form lime scaling in pipes (this is an extreme case of a hard water stain), boilers, water heaters and air conditioning units. The lime scaling results in higher fuel bills and serious damage to water pipes and heating systems. In water heaters minute amounts of scale results in the reduction of the water heater's efficiency by up to 15%. Scale functions as an insulating material and greatly reduces heat conductivity rates.

In water that is very hard it is virtually impossible to make a smooth lather when washing and soap usage nearly doubles in extreme cases. Hard water leads to the development of horrid grey-coloured soap remains ... which is another example of a hard water stain. These soap stain remains get stuck on clothes, glassare, food dishes and ceramic surfaces.

Degree of water hardness mg/l as CaCO3

• Very soft water 0-20

• Soft water 20-50

• Hard water 50-500

• Very hard water >500

There are a wide range of water usage articles which cover issues such as water usage in the house, filters, softeners, heaters and water in the garden as well. Links to topics change every time you visit the page