|
A filter is a device for straining substances in suspension
from a liquid or gas by passing the liquid or gas slowly
through cloth, paper, sand, ceramic tile, charcoal
or other porous media. Filters are sometimes homemade,
but usually purchased. Media is a substance that carries,
collects or holds some other substance. Filtration
media then is the sand, charcoal, ceramic tile itself.
A filter is used to remove impurities from water.
What is being filtered in a pond?
What’s being filtered in a pond is called the “load”.
The load in a pond is the amount of impurities and
nutrients that are in a pond at any given time. The
load comes from nutrients inherently in water, fish-waste,
leaves, cut grass, tree bark and other debris that
can collect in a pond, sink to the bottom and decompose.
The decomposed debris adds nutrients and impurities
to the pond. The nutrients are food for the algae which
if not checked can take over a pond. The load can exceed
the ability of the filtration system to remove the
particles. The filters can become clogged or can malfunction.
Any filtration system must be designed to handle the
load of that specific pond.
A Mechanical Filter
Traditionally ponds used filter systems that are
similar to pool filter systems. The purpose was to
remove all impurities from the water. Pool filters
can be expensive to purchase and to operate. Pool filters
are usually housed in an enclosure that needs to be
built and pipes need to run to that location. They
use external pumps that are loud and need to be silenced.
Ultra violet lights can be added to the filtration
process. By slowly sending pond water through a UV
filter all or most the impurities can be removed. Again
UV’s are expensive, need to be maintained and
they restrict the water flow. If the flow is too rapid
only part of the impurities in the water will be destroyed.
Pool filtration systems do work and can keep a pond
very clean.
A Biological Filter
About ten years ago biological filters began to be
used more and more and have become an alternative to
the traditional pool type filter systems. The theory
with biological filters is a bit different. Algae in
its various forms, pea green soup, string and surface
algae to name a few, are very unsightly in a pond.
Pond owners don’t like it and are constantly
fighting the algae problem. Biological filters have
been successful in removing algae. Algae need food
or nutrients to grow. Biological filters remove the
nutrients in the water which in turn starves the algae
and prevents its growth.
A biological filter removes these nutrients by adding
beneficial bacteria and enzymes into the pond environment.
The bacteria then consume the nutrients and starve
the algae, just like it is in nature. A biological
filter really provides a place for the bacteria to
live and grow. We usually refer to it as colonizing
the bacteria. Beneficial bacteria colonize in the media
provided in the pond filter. This is most often a filter
box that is at the top of the pond. The result is crystal
clear water.
|
