Pond Filtration
How do you know if your pond needs a filter?
If you are planning a koi pond, or wish to keep
a concentration of fish of any description, a filter
is essential. With existing ponds, the most obvious
indication is the quality of the water and the health
of the fish it supports.
Which
type of filter is best for your pond?
Your choice should be based on the size of the pond,
the number and type of fish and the area available
to accommodate the filter.
Filters can be divided into four categories:-
1.
Internal Filters
These are filters that are positioned in the pond.
They are usually only used in smaller ponds that
are lightly stocked with fish. These units incorporate
a pump, filter and UV in one easy to install unit.
2.
External Pressurised Filters
Water is pumped into the filter under pressure and
returned under pressure. The filter can be installed
discreetly at any level relative to the pond and
the return water can be pumped up to a waterfall
or used for a fountain jet. They are easy to maintain
but should not be used on heavily stocked ponds
or those with large koi. The Hozelock Bioforce and
Oase Filtoclear ranges are the best examples of
pressurised filters.
3.
External Pump Fed Filters
Water is pumped from the pond into the filter under
pressure, but drains out by gravity. You cannot
run a fountain using the outflow from the filter.
The filter must be installed with the outlet above
the pond water level. Pump fed filters are easy
to install and do not require any alteration to
the structure of the pond.
External
Punp Fed Pond Filters |
4.
External Gravity Feed Filters
These are usually only used if the pond has been
specially constructed with a sloping base and bottom
drains. The filter must be sunk in the ground so
that the water level in the filter is the same as
the pond. Water enters the filter by gravity from
the pond and is returned by the pump under pressure
and therefore can be used to power a fountain jet,
a waterfall or a venturi if required.
External
Gravity Feed Pond Filters |
