New pond syndrome is a common phrase to encounter when discussing or reading about fish health or husbandry issues.

Whilst it is a common and accepted concept, what is the actual underlying issue? When judging your new pond by human standards it is probably accurate to say that in many instances, new is considered best, not worst, so what is the issue?

Possibly the simplest way to understand the concept is to think of the water as a complex eco-system in its own right. This is not just a pool where the fish choose to swim but a 24/7 habitat in which the fish will respirate, eat and produce waste. To cope with all of this extra activity, the pond water needs to have a mechanism for processing waste products and other pollutants. These extra functions are carried out in nature by micro-organisms such as bacteria.

With your new pond installed, it will, more than likely be filled with tap water. In stark contrast to established pond water with its vibrant organic life, tap water has been meticulously cleaned and processed to pass very high hygiene standards.

As soon as you introduce fish to this freshly filled inert water environment, they will begin to pollute the water. Due to the almost total lack of bacterial life present in the water, the water will have no capacity for handling these pollutants. It is easy to understand how this will rapidly lead to issues of poor water quality and distress for your fish.

One of the key tools utilised in managing pond water quality is a biological pond filter. Unfortunately these are not a shortcut to avoid new pond syndrome. A biological filter uses exactly the same biological processes to manage water quality and requires a build up of bacterial growth over a number of weeks to function properly.

The key tool in avoiding issues is patience. A few weeks for your pond to settle with new plant life and a running filter will avoid many issues when fish are introduced. By introducing fish gradually, you will also give the water time to adjust. Bacteria in the filter will grow more rapidly in response to the introduction of fish and their resulting pollutants. This is a gradual process and patience will avoid overwhelming a delicately balanced system.