If you want to have a goldfish pond, but dread the thought of having to pull out a dripping slimy filter every few weeks so that you can change it, then you may want to take a close look at the option of using koi pond biological filters. The koi pond biological filter is designed so that it does not need charcoal and filter inserts to keep your pond clean.
Instead, in a koi pond biological filter, special little balls or pieces of tube are placed inside a black plastic box and covered with several layers of foam. Dirty water enters the filter, and goes through the foam, which traps bits of debris. The tube pieces or balls in the bottom of the filter are used to grow good bacteria, which clean the algae and dangerous nitrates from the water.
From there, the clean water is pumped back into the pond. You should not clean your filter more than once a year. If you need to clean out the filter because it has become blocked up, be prepared to wait six to eight weeks for the good bacteria to begin growing again.
Before you shop for a koi pond biological filter, you should figure out how many gallons of water your filter will be responsible for cleaning. This way, you will buy a filter large enough to handle your pond water volume.
While you can find a koi pond biological filter that does not do anything besides cleaning the pond’s water, you can also find filters that do much more. A combination filter, pump, and waterfall can provide plenty of flexibility. With a simple twist of a knob, you can turn on the fountain and adjust the height to suit your needs. During the summer, when evaporation is already causing your water level to drop rapidly, you can shut off the fountain without turning off the filter.
If your pond is suffering from an algae invasion, you may need to combine your koi pond biological filter with an ultra violet pond filter. This filter pulls the algae flakes together into clumps that are much easier for the biological filter to capture, leaving the pond water, plants, and fish algae free.