Never Stop Your Fish Pond Pump Unless For A Couple Of Minutes
Never switch off your pond pump for more than a few minutes if you keep fish in
a garden pond. A
circulating water pump drives a fountain or a waterfall and it adds character
and movement to your system. However ......
Its most important job is to provide life-giving oxygen to bacteria in the fish
pond bio filter.
A water pump works just like your heart does. The heart's job is to continuously replenishes your vital
organs with freshly oxygenated blood. The source of the
pond oxygen is not air directly rather it is oxygen transferred from the air and
then dissolved in water (air contains about 20% oxygen at sea level).
Not only fish in a pond need oxygen ... the nitrosomonas and nitrobacter
bacteria in pond
filters also need oxygen to be able to survive and purify the garden pond water. These
nitrosomonas and nitrobacter bacteria use up large amounts of dissolved oxygen
and this oxygen needs to then be replaced.
Think of running 2 pumps in a fish pond to make sure
you always have a back up and in any case this arrangement allows you to save
quite a bit of money if you choose the system properly.
How oxygen is made available to your koi or goldfish as well as nitrosomonas and
nitrobacter bacteria ....
Water absorbs oxygen at any interface between water and air.
absorb oxygen from air more
efficiently than large surface areas like the actual pond surface. Fountains work on this principle.
Colder water holds more oxygen than warm water
and windy days are better than still days for absorbing oxygen because they
effectively increase the surface area of the pond in contact with the air
through the action of making waves. The waves also serve the purpose of
mixing the oxygen rich surface layers with water deeper down ... this
happens as you'll often notice when waves crash against a lake's bank ...
here you'll see foam collecting. Water returning from this bank side tends to
sink to the bottom layers of the lake on its return journey up-wind (there
is a constant recirculation of water caused by wind action).
Water has more oxygen in it during the day than it does at night especially if
there are pond plants growing in the pond because the pond plants absorb oxygen
during the night and release it during the daylight while the photosynthesis
process is taking place.
A waterfall and a fountain are extremely useful in a pond because they increase
that interface between water and air.
Dissolved oxygen is used by your fish to breathe and most
people do realise this.
What people don't often realise is that water as it passes through the garden
fish pond filter has oxygen removed from it. The bacteria in your biofilter use
this oxygen to help them "digest" ammonia "food" from fish waste which is also dissolved in the pond water. Let me explain
the process in a simplified but
essentially accurate way ...
In order to digest ammonia from fish metabolic
processes each bacteria needs a small amount of
oxygen. This oxygen chemically combines (in fact oxidises) with the nitrogen
containing ammonia molecules to become nitrates. Ammonia and its chemical formula
is NH3. Notice that the ammonia formula contains no O ... for oxygen .... only N for nitrogen and H for
The nitrosomonas and nitrobacter bacteria, convert the waste ammonia to
nitrates by removing oxygen from water and chemically
swapping the "H" for
"O" . What was initially NH3 now becomes NO3 (chemical formula for nitrate).
This is what's happened ...
The nitrosomonas and nitrobacter bacteria have removed the H from ammonia and exchanged it for 3 oxygen
atoms. The H dropped from the ammonia molecule also combines with more O to form
H2O ... water. This process helps to explain why a considerable
amount of oxygen is needed to allow the bacteria to do their work. The only
place the oxygen can come from is that dissolved in the water.
So now you know .... never switch off your pond pump for any length of time if
you keep fish and certainly never during feeding.
Different types of pumps ...