Koi Pond Filter With Trickle Filters

Trickle Filter, Photo From makeakoipond.com

Trickle filters are filters in the koi pond that are designed for biological filtration of pond water in 'dry' mode. Dry mode filtration simply means that the filter media are not submerged under water. Trickle Filter also called trickle towers. Trickle filters allow water to freely flow out of the tank by means of an overflow. As the name implies, an overflow is a mechanism that allows water to just flow out of the fish tank when it reaches a certain level. Advance Trickle Filter is Bakki Shower Filter.


Trickle Filters reduce the nitrate level of pond water by exposing the water to a large surface area of good aerobic bacteria that consume nitrates. The large surface area is achieved by choosing filter media that has a high surface area-to-volume ratio, such as bio-balls (plastic balls that have pegs).
For trickle filters to work, however, their filter media need to be fully colonized by the good aerobic bacteria. This colonization occurs naturally with time, usually in 3-4 weeks after the pond is filled with water. Colonization may be accelerated by mixing some 'old' filter media in with the new ones, which in effect 'seeds' the new filter with a small colony of bacteria.

In the case of the trickle filter, the pond water is instead allowed to drip in small 'trickles' through the filter media, which are usually hundreds (or even thousands) of bio-balls stacked onto each other to form a column or tower. The primary purpose of trickle towers is to reduce the nitrate levels of the pond water and turn green water into gin-clear water.

How Does a Trickle Filter Work?

Trickle filters allow water to freely flow out of the tank by means of an overflow. As the name implies, an overflow is a mechanism that allows water to just flow out of the fish tank when it reaches a certain level. Overflows are also used in swimming pools and reservoirs to control the water level and when and where water flows out of the pool or reservoir. In the case of a trickle filter, once the water flows out of the main tank by means of the overflow, it is collected or channeled into a drain pipe.

The drain pipe channels the water to the top of the tower. At the top of the tower is a spinner, spray bar, or distribution plate. A spray bar is a horizontal tube with holes in it to spray water across the top of the tower. A spinner is just a spray bar that rotates. this rotation is usually provided by the water itself, either coming through a screw or impeller to get to the spinner, or because the holes are all on one side of the tube and the water spraying out of the spinner pushes the spinner back the other way slightly. A distribution plate (or drip plate) is just a plate of aquarium safe plastic of acrylic with holes drilled into it to allow the water to drain in many places.

Trickle Filter Work, Pic From forum.o-fish.com

Trickle Filter Diagram The spray bar, spinner, or drip plate spreads the water out across the top of the tower more or less evenly. The tower is called a tower because it is usually relatively tall and narrow and rises above the sump.

The water the "trickles" through the biological filter media drawn downward toward the sump by gravity. As the water flows down through the media, it is exposed to free-moving air, which keeps the water oxygen rich. The high oxygen levels in the water in the tower improves the efficiency of the nitrifying bacteria providing biological filtration.


Source:
http://www.firsttankguide.net/trickle.php
http://www.koiandponds.com/tricklefilter.htm