Aeration simply means adding oxygen to the water by keeping it moving and free flowing through your pond’s circulatory system. This is vital for the health of our koi and also just a great way to keep your pond looking great.
Koi ponds and plants (including all forms of algae), organic life and of course the koi fish themselves consume oxygen. Koi are rather special in that they need a considerable supply of oxygen in the water for their survival and well-being. The more algae and bacteria that are in the water the less oxygen there is for fish.
There are lots of things in your pond that are competing with your fish for oxygen. Plant life consumes oxygen during the night and gives off carbon dioxide. This process is reversed during the day. The more organic stuff that is in the pond (fish, plants, decaying material) the higher the oxygen demand of the entire ecosystem. Decaying organic matter also uses oxygen as it is converted into waste and the ‘dirtier’ the pond. This means the more trees your pond is situated under, the higher the requirement for oxygen. The warmer the weather is the less oxygen there is in your pond.
Waterfalls, and air pumps can supply oxygen. Waterfalls are extremely efficient when it comes to providing good aeration but many ponds just don’t have them. Many people turn these water features off at night, which during a summer night is just when the koi need to be aerated the most.
There are several ways to aerate your pond but the most common ways are to install a water pump with an airstone, a commercial aerator such as a bead stone pump or a waterfall.
Airstones are ceramic, synthetic or natural stones through which air is blown by an air pump. These stones are characterized by hundreds of tiny holes, which create bubbles in your pond system. This allows more oxygen to circulate through your pond’s ecosystem.
You can also buy Plexiglas tubes that sit on the bottom of the pond and funnel oxygenated bubbles up towards the ponds surface. These commercial aerators are offered in both battery operated and outlet operated versions.
An external pond filter or waterfall tank can be positioned against the shallow edge of the pool to create a waterfalls. Just make sure that the waterflow flows to just a trickle as too much water hurts the koi.