| Oxygen is
vital to all living organisms living in your pond. Seems simple enough
to understand that fish need air yet, what if the oxygen level is too
low? What increases oxygen concentration? Why is more better and what
are the benefits? How can we test the oxygen level or content? How can
we get oxygen towards the bottom of a deep pond? The following should
help.
Low oxygen concentrations can cause
fish to be increasingly susceptible to disease and even die suddenly.
The sad part is the large fish die first when the oxygen level is too
low. Oxygen concentration decreases when; temperature increases especially
above 80 °F,
over stocking, heavy amounts of decaying matter exist in the pond or
with either poor or no circulation of pond water.
Moving water helps mix air into the
water and provides a means of natural gas exchange into the
atmosphere. A stream, waterfall and jets can perform this very well. By
moving the water surface of a pond with pond
jets, the atmosphere and
water contacting each other repeatedly will increase the oxygen
content of the water. Some choose to add an air pump and air stone to
increase oxygen concentration. The mixing takes place at the surface
as the bubbles burst and with the movement of the surface water moving
away from the rising air and water column.
Colder water contains more oxygen
than warm water. Some choose to turn off water features during winter
months. This does two things. It saves on electricity and slows down
the cooling of the pond. Some refer to this as "Turbo
Cooling". The disadvantage to turning off the pump during
winter's
coldest months is that the biological filter will be slow in starting
up again as temperatures begin to rise.
By increasing the "oxygen"
levels in the pond water, it will promote an overall healthier
pond. One important area that higher levels of oxygen saturation
help is in better promotion of good biological bacteria known as aerobic bacteria. Aerobic bacteria are the good
bacteria in
our pond that like oxygen. They grow and eat dead decaying plants,
algae and
pond muck up to 30 times faster
than anaerobic bacteria (an-aerobic). Anaerobic bacteria live and grow in the absence of oxygen. Maintaining
a constant supply of oxygen greatly improves the ability for the
aerobic bacteria to thrive and keep your pond bottom cleaner, the
water clearer and fish healthier.
There is a point of oxygen
saturation. To find your level of dissolved oxygen or oxygen
concentration, you could use a test kit. Or even better are the
electronic type testers called "Dissolved Oxygen Meter". The
meters are not cheap and start around $150 and up. While an O2 test kit
can cost around $12. The advantage to the Dissolved Oxygen meters is
that the probe can be lowered to test the oxygen level at different
levels for those with deeper ponds.
Ponds that are designed with bottom
drains permit better oxygen disbursement towards the bottom because
water usually enters the pond's top surface and is drawn out from the
bottom drain. This method recirculates the pond's total water column
better than those that do not draw the water from the bottom. More
oxygen content close to the bottom promotes the good bacteria which
consumes waste that settles on the bottom. Ponds
that are in the colder climates like the United Kingdom,
sometimes will draw the water from the mid-pond level permitting the
bottom half of the pond water to remain warmer for the fish.
Note: Decaying plants in a very low
oxygen level pond can create a toxic dissolved gas known as Hydrogen
Sulfide.
So as we can see there are many benefits
and life supporting reasons to having adequate oxygen concentration.
So, when is comes to oxygen in your pond, more is better!
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