The pH scale is a measure of how acidic or alkaline a substance is. If a substance has a pH value of 7, it is neutral, neither acidic or alkaline. Acids have pH values of under 7, and alkalis have pH values of over 7.

The pH value of water determines whether it is hard or soft. The pH of pure water is 7/neutral, water with a pH lower than 7 is considered acidic/soft and water with a pH greater than 7 is considered hard/alkaline.

Both very hard and very soft water can be problematic for fish and plant life. For Koi Carp enthusiasts managing pond chemistry is particularly important, the water quality must be stable and within the fish’s physiological limit, slightly hard/alkaline water is best.

Essentially there are 3 problems with pond water pH that can affect the pond’s inhabitants:

• The pH is consistently too low - the water is acidic/soft.
• The pH is consistently too high – the water is alkaline/hard.
• The pH is unstable and prone to fluctuation.

Fortunately for Koi keepers, tap water tends to be slightly hard/alkaline but as soon as that water has filled the pond, its characteristics will begin to change and this change should be monitored.

If pH drops to less than 7.0

A drop in pH in a pond to below 7 will lead to dramatic changes in koi health, particularly if it is long term. Colours in koi are likely to fade through the deposition of excess mucus while in extreme cases fish may even be seen to gasp at the surface.

If the pH exceeds 9.0

An excessively high pH is less extreme on koi than a low pH but should still be avoided. The symptoms of an excessively alkaline pond will cause koi to secrete a slimy mucous film and also lead to gasping at the surface, very similar in fact to those when koi experience acidic conditions.

Many aquatic plants will not thrive in excessively hard water.

If your pond suffers from blanket weed or string algae, particularly if it has excessive algae build up at the sides, the water may be excessively hard. The easiest way to soften hard water is by mixing it with soft water e.g. from a home water softener unit, visit http://www.electrostoreonline.com for information on water softeners.

More than 60% of Britain has hard water, to see a map of hard water areas in the UK go to: http://www.electrostoreonline.com/Water-Conditioner.aspx

For more information about electronic water softeners visit Electrostore Online. You will also find information about conservatory vent controllers, blanket weed control solutions, and PH soil meters.