Filtration is the most misunderstood aspect of pond care. What is considered "good" filtration varies by region and pond. Good filtration means something different to the Koi keeper than to the water gardener. Poor filtration often goes undetected until it is too late. To protect yourself and your pond be well-informed.

Why filter? Bodies of water collect debris. A good filter provides control over waste accumulation, water clarity and water quality. Unfiltered ponds tend to have unreliable clarity and often need to be drained and cleaned to maintain a healthy environment. Cleaning like this kills any natural balance of a pond, which can only be achieved through stable aging.

Mature ponds support fish and plants without algae problems. Changing all the water of a pond or excessively large amounts disturbs the aging process. But don't get fooled, clear water doesn't always means clean water. This is a common misperception. Pond ecology is not that simple. Even if you don't want fish now, a filtered pond is easier to take care off and you might change your mind later on. A water garden is not complete without fish. A well designed pond is a living ecosystem, where birth, death, decomposition occurs. As organic debris, fish wastes, uneaten food and dead organisms are introduced to the pond it begins to decompose. The organic debris is called nitrogenous waste. As it decomposed it produces toxic chemicals. The nitrogen cycle is a multi-staged process that relies on microscopic organism to break down nitrogenous waste and convert it to non toxic chemicals. These unseen organism are called the nitrifying bacteria. A pond is considered established once the nitrogen cycle continues over and over again. Once a pond is fully stocked a mayor disruption in the cycle can be deadly. Good filtration helps cope.