There are several types of filters that you can use.
Basically
Filters can be divided into three broad classification.>
-
Mechanical filters
-
Biological filters
-
Combination filters
For small ponds mechanical or biological filters and water changes are
effective;
however for large ponds combinations of the two are required.
You can drain
ten gallons of a hundred gallon pond, but it is just not
practical to drain
several hundred gallons of water, from a two or three
thousand gallon pond,
and refill the pond each week. Commercially made
filters have a strong
tendency to be over rated for the size of pond that
they can handle, by
selling an undersized filter, the filter seems
less expensive than
the competition's filter does. It makes sense to buy a
filter that's oversized
by the manufacture's specs.
Mechanical Filters
Mechanical
filters remove suspended particles for removal. When the
particles are
removes, they do not contribute to the Biological Oxygen Demand
of the
pond.
Biological Filters
Biological
filters use plants, animals and bacteria to convert toxic liquid
wastes
like ammonia to less toxic compounds and or use the toxic compound to
fertilize
plants.
Both
Mechanical and Biological filters do have a certain amount of the other
type of filters qualities, but this is not designed into the filter and
is coincidental.
After the water is
filtered, it is usually aerated to add oxygen and remove
carbon dioxide
and ammonia. Fountain heads or water falls are usually used
for this.
Combination filters
Combination filters
are designed to use both of the above filters in a single
system. They
can range from simple "boxes" dropped into the water, or on the
side of
the pond to very technical and complicated systems capable of giving
the
water a very clear and "polished" quality.
