These pages are
reprinted from www.gotalgae.com, courtesy of www.kascomarine.com.
Quality Problems Introduction
quality problems have numerous causes and various symptoms. These
problems can be thermal,
aquatic plants, or organism
related. A single pond can, and will, have several of these problems
occurring simultaneously because they are all related with cause
and effect relationships.
of the time, the best thing to do when deciding to address your
pond or lake water quality problems is to consult a local, reputable
lake management professional. They should have the equipment and
knowledge needed to diagnose the problem and ways to fix it, as
well as being up to speed with local, regional, state, and federal
restrictions and regulations pertaining to pond and lake management.
It is a good idea to have some background knowledge, however, so
you will be able to tell if the suggestions make sense and are worth
quality problems cover a wide array of individual cause and effect
relationships. As stated in the first paragraph, the basic breakdowns
of poor water quality are typically related to temperature, nutrients,
pH, aquatic plants, and fish and other living organisms in the water.
If you have a good idea of what your pond or lake is suffering from,
you can see more detailed information on these subjects in the Aeration,
Temperature Solutions, Nutrient
Solutions, Aquatic Plant
Solutions, Algae Solutions,
and Fish & Wildlife pages. Below
are a few water quality parameters and some information on each.
Back to Top
Oxygen (DO) is on of the most important water quality parameters
concerning your fish and other aquatic life in your pond. It is
a measure of the amount of oxygen dissolved in the water that is
available for aquatic life and is typically measured in Parts Per
Million (PPM). Cold water has the ability to hold more dissolved
oxygen than warm water.
oxygen levels fluctuate with the time of day and the activities
in the pond. During the nighttime hours, plants stop producing oxygen
in the photosynthesis process and actually start using up oxygen.
Fish and aquatic life activity such as feeding also uses up dissolved
oxygen in the pond. Another large dissolved oxygen user is bacteria.
During the decomposition process, bacteria use oxygen to breakdown
organic material. During a plant or algae die off, decomposition
rates greatly increase and so does the demand for oxygen. This can
drastically drop the dissolved oxygen rates and cause fish die off.
oxygen is provided from plants during the photosynthesis process,
diffusion of oxygen at the air-water interface, wind/wave action,
and cascading or splashing water. However, this often is not enough
to support large fish populations, especially during the late summer.
A great way of adding supplemental dissolved oxygen is to add an
Back to Top
problems are caused from uneven warming or cooling of your pond.
During the summer, the surface water is warmed and the colder, denser
bottom water does not get warmed as much. This causes two distinct
layers of water with a dividing line, called a Thermocline. The
problems associated are due to inadequate mixing of the water. Oxygen
diffused into the water from the air is not mixed with the cooler
bottom water. Therefore, you have a warm, oxygenated layer of water
on top of a cool, low oxygen level layer at the bottom. When the
surface cools in fall, it becomes denser than the bottom and the
pond "turns over" call Turnover. This causes a mixing
of all water and an overall decrease in dissolved oxygen levels.
Turnover can lead to massive fish die off and major problems with
Back to Top
problems are the most common cause of aquatic plant and algae problems.
Nutrients can enter the pond naturally from leaves of nearby trees,
die off of existing aquatic plants, wildlife waste, etc. The biggest
problem is with unnatural, non point source pollution or runoff.
The runoff of nutrients from fertilized lawns, farm fields, cattle
pastures, grass clippings, roadways, etc. add large amounts of nutrients
to your water. This sets off a major aquatic plant and algae growth,
which leads to more problems.
Back to Top
Plant and Algae Problems
plant and algae problems, as stated, are typically caused by increased
nutrients in the pond. Plants produce energy through photosynthesis.
During this process, they use sunlight and carbon dioxide to produce
energy and oxygen as a byproduct. However, during the night when
there is not sunlight, the plants use up oxygen and give off carbon
dioxide. Therefore, oxygen levels drop all during the night in your
pond and could harm your fish and overall water quality. Also, when
the plants die off, especially a massive algae bloom die off, the
oxygen levels drop drastically over a short period of time. When
the plants die, bacteria begin to decompose the organic material
and use up oxygen quickly and causing the overall dissolved oxygen
in the pond to drop.
Back to Top
Living Organism Problems
living organisms can also cause problems in your pond. Wildlife
that use your pond are adding nutrients with their waste and can
create an unbalanced pond ecosystem. Too many or too few fish and
of the wrong species can also have a negative affect on your pond
and the overall water quality. Also, as stated earlier, bacteria
are a major player in water quality of your pond. They breakdown
the organic material during decomposition. The two ways of decomposition
are aerobic and anaerobic. Anaerobic occurs without oxygen present
and is a slow process that has byproducts of sulfur dioxide and
other sulfur compounds which give you the rotten egg smell in your
pond sediment. It is also not the greatest for your fish. Aerobic
decomposition occurs in the presence of oxygen and is much quick
with a byproduct of carbon dioxide.
Back to Top
of the water can pose a water quality problem. Lake of clarity or
turbidity can have several causes, but the effects are typically
the same, cloudy water and decreased aesthetics of the pond. The
cloudy water can prevent sunlight from reaching the aquatic plants
in the pond, which wouldn't be bad if your pond is overrun with
weeds. However, most ponds with turbidity problems do not have much
aquatic vegetation to begin with because the cloudiness of the water
is caused by bottom sediment mixed up in the water column. The lack
of vegetation allows for the sediment to be stirred up and then
it blocks the sunlight to prevent further growth. A cloudy pond
can also decrease your enjoyment of your pond. Typically, the turbidity
is from stirred up sediment, such as clay, or it can be organic,
like planktonic algae. If the turbidity is caused by bottom sediment,
to fix it is usually a waiting game, however there are some products
available which will help remove the cloudiness. If it turbidity
is caused by organic growth, the organisms can be treated.
Back to Top
The pH level is a numeric value
that indicates the relative acidity or alkalinity of the water on
a scale of 0 to 14, with neutral at 7. Acidic water has pH levels
below 7 and basic or alkaline water has pH levels above 7. Most
lake and pond organisms prefer pH levels of 6.5 to 9. The pH levels
in a given pond can fluctuate daily and is determined by complex
relationships between carbon dioxide, hardness, alkalinity, photosynthesis,
and respiration. If pH levels are not maintained, there could be
negative affects in your pond.
or basic materials such as carbonates, hydroxides, phosphates, and
bicarbonates are common in pond environments. Alkalinity is the
buffering capacity of a pond or lake. This buffering capacity is
important to allow pH levels to remain constant even with the introduction
of acids from non point source pollution and acid rainfall. Of pH
levels are too acidic, lime is a common additive to bring the pH
back to normal levels. Maintaining a healthy pH for your pond will
help your pond organisms to thrive.
Back to Top
hardness is the measure of divalent ions in the water. Some common
causes of hardness are calcium and magnesium carbonate. If you go
through a lot of salt in your water softener in your home, and you
pond is in your backyard, there is probably a good chance you have
hard water in your pond as well. Hard water can decrease the effectiveness
of certain algae and aquatic plant chemical treatments. It can also
limit the growth of plankton in your pond and limit fish growth.
Back to Top
Theme: Oxygen and Water Movement
can see from a general overview of the common water quality problems,
water movement and oxygen play a major role in each problem and
effects of those problems. A balanced pond ecosystem always includes
adequate levels of oxygen. Aeration is
a great way to combat these problems and limit the negative effects
of them. Adding an aeration device will add vital dissolved oxygen
to your pond and also water movement.
water movement will help combat the temperature problems by mixing
the water and lowering or eliminating the thermocline. The added
oxygen will help reduce the negative effects of Turnover. If the
pond does experience Turnover, it will be a much less drastic event
and the pond will be able to handle the mixing much better.
agitation at the surface will help mix the water and vent off some
of the extra nutrients entering your pond. Also, the water movement
will help desirable aquatic plants out compete more undesirable
ones that use up the extra nutrients in your pond.
extra oxygen added from the aeration device will buffer your pond
from an aquatic plant or algae die off so your fish do not die.
Even when oxygen levels are low after the die off or at night, the
aerator is providing oxygen for the pond. Also, the water movement
will help limit the growth of algae and other aquatic plants. It
will limit the amount of sunlight that is able to penetrate the
water and decrease plant growth.
dissolved oxygen is also great for the fish and wildlife in the
pond as well. Oxygen will allow the decomposition process to occur
aerobically, which is faster and a more efficient way. The byproduct
of carbon dioxide will be vented off with the added agitation at
the surface, as well.
Back to Top
Can We Help?
oxygen is a balancing agent in your pond. Most water quality problem
causes and effects are related to an unbalanced system and one that
lacks adequate oxygen levels. Aeration tends to create a healthier
pond or lake with its added oxygen levels, water agitation at the
surface, and mixing of water throughout the water column. There
are several aeration devices available and you can see more detail
in the Aeration page.
offers several models and sizes of aeration equipment to suit you
ponds needs. Kasco's Pond Aerators are a surface agitator/aerator
that floats at the surface and splashes the water. This model is
great for adding oxygen to the pond and has a high flow rate. These
are Kasco's most efficient model at adding oxygen. They come in
1/2, 3/4, 1, and 2hp sizes.
Water Circulators are horizontal mixers of water. They float at
the surface on a horizontal float, or can be mounted to a dock or
below a boat. These models are great for water movement and directional
flow. These are Kasco's most efficient models at moving and mixing
deep water. They come in 1/2, 3/4, 1, and 2hp sizes.
Aerating Fountains are the best of both worlds when you are looking
for a nice display in your pond. They add oxygen, water movement,
and give you a beautiful display feature in your pond. They come
in 1/4, 1/2, 3/4, 1, and 2hp sizes.
Back to Top
These pages are reprinted from www.gotalgae.com, courtesy