These pages are
reprinted from www.gotalgae.com, courtesy of www.kascomarine.com.
Most Common Pond Problem
complaints about pond water
quality and overall pond problems have aquatic
weeds and algae somewhere
in the equation. Excessive aquatic plant growth and algae can turn
any pond, lake, or body of water into an eye sore. Excessive growth
can also cause problems with overall pond health, fish health, odor
problems, etc. So not only does your stagnant, overgrown pond or
lake look bad and decrease your enjoyment of your property, it also
is slowly "killing" itself and its inhabitants.
main cause for excessive algae and aquatic plant growth in a pond
or lake is an abundance of nutrients. Phosphorus and nitrogen combined
with carbon dioxide are the main supplies that can turn your pond
from clean to green very quickly. All aquatic plants and algae make
their own energy through photosynthesis which uses sunlight and
carbon dioxide to create energy and oxygen as the byproducts. The
other key ingredient to plant growth and health is nutrients, the
main two being phosphorus and nitrogen.
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and nitrogen are all around us, and more importantly around your
pond or lake. Since most plant life, aquatic or terrestrial, rely
heavily on both, they all contain large amounts of these nutrients.
Therefore, the grass, trees, shrubs, cattails, etc. that surround
your pond or body of water all are potential sources of nutrients
for your pond, as are the existing aquatic plants and algae currently
in your pond. Every time you mow your lawn or leaves fall into the
pond, nitrogen and phosphorus are added to your ponds ecosystem.
Also, every time your aquatic plant growth dies off or is killed
off by a treatment method, those nutrients that were in the plants
are released back into the system for the next generation of plant
are several other sources of nutrients that find their way to your
pond as well. Grass clippings, leaves, and existing plant growth
are "natural" contributors to extra nutrients, but often
times the most destructive are the "unnatural" contributors.
These typically consist of lawn fertilizers, garden/flower bed fertilizers,
farm fields and/or pastures, and wildlife. When golf fairways and
greens, lawns, gardens, flower beds, and farm fields are fertilized,
there is often large amounts of excessive nutrients that are not
used quick enough by the terrestrial plants or that the soil cannot
hold. When the first rain or irrigation comes along in these areas,
those extra amounts of nitrogen and phosphorus "runoff"
into the low areas. Most ponds and lakes are the lowest spots in
a given area because they need to be to be able to hold water. Therefore,
the nutrients that runoff are flowing directly into your pond or
lake and providing aquatic plants and algae more than enough to
thrive. This is known as non point source pollution. Golf courses
are continually running into this problem because fertilizers are
needed to keep greens and fairways up to par. The same thing is
true for farm pastures, only this time the nutrients are coming
from the animals themselves. Also, the wildlife
that uses your pond frequently are making nutrient deposits. The
biggest culprits of wildlife contributions are ducks and geese that
can swarm to a pond or lake.
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to Limit Incoming Nutrients
that you know the major contributors to nutrients in your pond or
lake, you can try to limit the amount that is introduced. This often
times is a long process that is has gradual results because most
aquatic plants and algae do not require large amounts of nutrients
to thrive so more than likely the muck in the bottom of the pond
is filled with nutrients not even being used. However, there are
ways to limit new nutrients from entering you pond.
examine your pond and the larger area around it. Determine where
most of the nutrients are coming from. Trees that surround the pond
typically have other benefits that greatly out weigh the amount
of nutrients they supply with leaves so those usually stay put.
Look closely at elevation changes and where fertilizers and grass
clippings can runoff into the pond. Remember, most ponds, especially
retention ponds, are designed to be catch basins for the entire
area so nutrients can be coming from lots of places.
you have determined where the nutrients are coming from you need
to try to block them from your pond. If most are from lawn fertilizers,
limiting the amount used is a very good start. If the amount of
fertilizers cannot be controlled (coming from someone else's property),
something needs to be in place to buffer the nutrients from the
pond. This step has a lot to do with personal taste. A burm or raised
barrier can be created to stop the flow of runoff and divert it
to a flat area where it can be used by other terrestrial plants.
Another good way of limiting the nutrients is planting quick growing
native plants around the pond that can intercept the nutrients and
use much of the available nitrogen and phosphorus before it gets
to the pond. There are many varieties of terrestrial vegetation
that can make your pond setting even more beautiful while using
the nutrients that are supplied by runoff. You can also introduce
desired aquatic plants that will use up nutrients and beautify your
pond. This again is often dependant on personal taste and your local
garden center should have some ideas of native plants that can do
the trick. A great aquatic plant is Chara. Chara uses up a lot of
nutrients and serves as a hiding place and food source for fish,
wildlife, and insects in the water.
the nutrients are coming from lawn clippings and leaves, you can
do a few simple steps like bagging the clippings when you mow, raking
leaves more often, and also raking leaves out of the pond near the
shore. Every little bit helps. If you have a duck or goose problem,
there are several deterrents available on the market that work in
varying degrees of success. Keeping wildlife out of the pond is
often the most difficult part of nutrient control, however.
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that you have successfully used, diverted, or blocked much of the
nutrients entering the pond you can try to remove the existing nutrients.
Again, this is a slow process, but every little bit helps. If you
treat your aquatic vegetation or algae, the plants die, but the
nutrients are still available while the vegetation is decomposing.
By physically removing the vegetation, you are removing large amounts
of nutrients. This can be done by cutting or raking the aquatic
weeds that are firmly rooted and collecting the fragments that float
to the top. It is important to remove the cut weeds from the pond
and far enough away that they won't get blown back in when they
dry or get washed back in by rain. They make great fertilizer for
way to remove the nutrients is to remove the decomposed organic
matter or pond muck at the bottom of the pond. This is referred
to as dredging and can be very costly and a large project to undertake,
but it is often the quickest way to remove large amounts of nutrient
rich soil and organic matter from your pond.
"binders" can be used to help eliminate the existing nutrients.
Aluminum Sulfate, or Alum, is used to clear up muddy or cloudy water
and remove phosphorus. Barraclear is a fairly new product with active
ingredients of Alum, bentonite clay, and a buffering agent to prevent
pH change. It binds phosphorous available in the water to starve
plants. The amount required is dependent on the existing levels
of phosphorous within the pond.
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Aeration Can Help
also plays a role in curbing the effects of excessive nutrients
in a pond or lake. As discussed in detail in the Aeration
section, adding an aeration device provides many benefits to a pond
and can help limit the amount of aquatic plant and algae growth
to begin with. Aeration adds extra oxygen to your pond or lake and
also helps to evenly disperse that oxygen throughout the water column.
This is very important when it comes to the decomposition of organic
discussed above, when aquatic plants and algae are treated or die
off naturally, they still provide large amounts of nutrients to
the pond ecosystem. The muck in the bottom of the pond is the result
of years of decomposing organic matter. The decomposition process
takes place in one of two ways or a mixture of both. These are anaerobic
and aerobic decomposition.
decomposition is the process of breaking down organic matter with
a lack of oxygen. Decomposition of any sort is a rather slow process,
but decomposition without oxygen is even slower. It is also a less
complete decomposition and has byproducts that are often undesirable,
such as sulfur dioxide or sulfuric acid. This is what gives your
pond and pond muck that rotten egg smell. This is not only a nuisance
to you, but also can be for your fish and other aquatic life.
decomposition is the process of breaking down organic matter in
the presence of oxygen. This is a much quicker process than anaerobic
decomposition. It is also a more complete decomposition and its
main byproduct is carbon dioxide which does not leave the foul odor
sulfur dioxide does. The only way to have aerobic decomposition
is to have sufficient oxygen for the bacteria and microorganisms
during the decomposition process. This is where a Kasco Pond Aerator,
Aerating Fountain, or Water Circulator comes in.
Kasco aeration device will add oxygen to the pond and mix the pond
water making sure there is oxygen for the decomposition process.
Over time, this will speed up the overall decomposition processes
within your pond and help eliminate the rotten egg smells and other
foul pond odors. Also, the agitation of the water will help vent
off some of the carbon dioxide that is produced by plants as well
as during decomposition and there will be less available for plant
growth. Some nutrient compounds are also able to be vented when
exposed to the air. The process of removing the nutrients by converting
organic matter or sludge on the bottom into carbon dioxide and then
venting those gasses off is known as bioaugmentation. Bioaugmentation
is a long process, but over time, helps to eliminate some of the
build up of nutrients.
the aerobic decomposition process will be faster, it will start
to make up ground on the years of build up in the pond, over a long
period of time. It will also help limit the amount carbon dioxide
available for plants. A Kasco aeration device used with the other
methods discussed earlier, like diverting the runoff, planting desired
vegetation that can use some of the extra nutrients, and cutting/raking
aquatic weeds out of the pond will gradually renew and rejuvenate
your pond. You will be slowing, stopping, and reversing the nutrient
loading your pond is currently going through and creating a cleaner,
healthier pond over time.
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These pages are reprinted from www.gotalgae.com, courtesy