Controlling Algae in Farm Ponds - YouTube

Hello, my name is Todd Sink and I'm the Fisheries Extension Specialist with the Texas A&M AgriLife

Extension Service. As you can see here it's spring time in Texas most of the trees are

beginning to bud out and most pond owners are once again getting back out to visit their

ponds, and many of you are seeing an all too uncommon problem. Some people call it

moss, some people call it pond scum, but what it is in fact is filamentous algae. Today

with my crack team of undergraduate students, we will be showing you how to identify the

various types of algae and how to manage it in your pond setting. Hi, my name is Jesse

Gwinn. There are three different types of algae commonly found in farm ponds and small

lakes. These are filamentous, planktonic, and macro algae. Filamentous algae are made

of single cells that form long visible chains, threads, and filaments that intertwine to

resemble wet cotton or wool. This type of algae grows along the bottom of the pond in

shallow areas, and then floats to the surface to form mats commonly referred to as pond

scum, or pond moss. This type of algae is unsightly and may interfere with swimming,

fishing, or other recreational activities. Hi, my name is Mikayla. Another type of algae

you can encounter in your pond is plank-tonic algae. This algae is microscopic and free

floating algae that exists in the top few feet of a pond or lake where the sunlight

penetrates. This type of algae is normal and in fact desirable and essential for the ponds

food turret as it provides food for microscopic animals that are eaten by fish fry and other

pond inhabitants which ultimately support a larger fish population. They exhibit seasonal

abundance, often blooming in the spring and sometimes summer, coloring the pond different

shades of green, blue-green, or brown. The natural degradation of the algae blooms can

lead to oxygen depletion and fish kills in the pond. Hi, my name is Hannah. One of the

types of algae that you can encounter in your pond is macro-algae. There are two main types

of macro-algae found in Texas ponds. Chara and Nitella. Chara, or Muskgrass is a grey-green

branch, multicellular, macro-algae with whirled branches that is often mistaken for an aquatic

plant, but can be distinguished by it's lack of flowers. It has a grainy, or crunchy texture,

does not extend above the water surface, and has a musty, almost garlic-like odor. Chara

prefers alkaline, hard-water ponds and grows in rows along the muddy bottoms in calm waters.

It is an undesirable species because it carpets the bottom, crowds out other species, and

grows rapidly, quickly becoming a problem. Nitella is another type of multicellular,

macro algae that are branched, do not produce a flower, and do not extend above the waters

surface. Also known as Stoneworts, this algae has no odor, is soft to the touch, and light

to dark green in color with forked, bushy branches. Like Chara, it grows in rows, attached

to the muddy bottoms of calm waters, and is undesirable because it can carpet the bottom

of the pond and crowd out other desirable species. Biological controls for macro algae

and filamentous algae include Mozambique Tilapia and Triploid Grass Carp. Mozambique Tilapia

will consume some filamentous algae and some macro algae, such as Nitella, but typically

provide limited, if any control. Additionally, as a warm water speices, Mozambique Tilapia

cannot survive in temperatures less than 55 degrees farenheit. So in all but far southern

Texas climates, they must be restocked each spring. Triploid Grass Carp will eat filamentous

algae, but because it is not a preferred food item, they will consume other types of submerged

vegetation before filamentous algae. Therefore, they are not typically a reliable control

for filamentous algae. However, Grass Carp readily consume macro algae such as Chara,

and Nitella. In Texas, only Triploid Grass Carp are legal and a permit from the Texas

Parks and Wildlife Department is required before they can be purchased from a certified

dealer. Mozambique Tilapia are the only legal Tilapia species that may be purchased in Texas

for pond stocking. Another way of controlling your algae is through chemical controls such

as copper sulfate. When using copper sulfate, the aqueous form is recommended. Although

it may be cheaper, the granular form requires more effort because it must be dissolved in

water and then sprayed onto the pond. Copper sulfate only works as long as it is in the

water column, so if crystals or pellets are thrown into a pond, they will will sink to

the bottom where they will not be effective in controlling algae. Copper sulfate is not

effective in hard or high alkalinity waters, because it binds with the calcium in the water,

forms a precipitate, and renders the copper ineffective as an algaecide. Copper sulfate

is not effective in cold water. It's toxicity to fish also increases with higher water temperatures,

and it should not be applied during the summer. Another method of controlling algae is chelated

copper. Chelated copper comes in an aqueous form that must be sprayed over the pond. Unlike

copper sulfate, Chelated copper doesn't precipitate in high alkalinity waters. It is also more

effective in waters with lower temperatures. Chelated copper stays in solution and remains

active for longer because it releases the copper ion more gradually than copper sulfate.

When applying your copper compounds to pond algae, you can either use a hand pump style

sprayer or a backpack style sprayer such as this, or you can use a larger, commercial

type sprayer that either goes in the bed of a pickup truck, or on the back of a 4-wheeler.

When you're applying copper, it is important to remember that copper is a contact herbicide,

so it's only going to be active on the algae that it actually comes in contact with. Therefore

it's important not just to dump it in the pond, you need to spread it over the surface

of the algae which means you need to spray it on. Remember, when you're using copper

sulfate, I want to stress again, you need to dissolve crystals in water before you apply

it and then spray it on. As you can see in this instance here, we already have a chelated

copper complex mixed up with our water, copper algaecides do have a blue color due to the

copper in them, and it is very important not have these compounds come in contact with

your skin because it will dye you blue and you will look like a smurf for a long period

of time. Always make sure you use proper safety attire and make sure you wear a good set of

gloves. All copper compounds can be toxic to fish if they are used above the labeled

rates. Be sure to test the ponds alkalinity and adjust copper treatments to alkalinity

concentrations. Be very cautious when treating a pond with an alkalinity of less than 50

ppm, as copper can be toxic to fish. Never treat ponds with an alkalinity less than 20

ppm. Above all, follow all label instructions when applying chemical controls. Aquatic herbicides

are not toxic to fish when properly applied according to the label. A final way to control

the algae in your pond is through physical control. Filamentous algae and macro algae

can be physically controlled by using a rake, a seine, a wire screen or another similar

device, or by physically cutting the algae or removing it from the pond. However, physical

control methods such as these are generally laborious and short lived, as the algae will

recolonize very quickly afterwards. Many companies make cutters and rakes that can be used to

remove the algae from the ponds. Another method of physical control involves using non toxic

dyes and colorants to shade the pond and limit sunlight penetration that promotes the algae

growth. Dyes and shading products are made by a company such Aqua Shade, Blue Springs,

or Crystal Blue, however this sort of control method may suppress the natural food chain

of the pond by reducing the plank-tonic algae that food chains of the ponds are based on.

Shading the pond can also be achieved by using a physical barriers to sunlight penetration

such a shade mat. Prevention is usually easier and more effective than treatment. The most

important key to preventing the growth of algae is to reduce the amount of nutrients

entering the pond. Creating a 10 to 20 foot buffer around the pond with taller vegetation

to filter excess nutrients, reducing the amount of fertilizer used in drainage areas of the

pond, and locating septic fields far away from ponds can help keep the excess nutrients

from entering the ponds. Another option is to aerate the pond. Aerating with a bottom

diffuser increases the level of dissolved oxygen at the bottom of the pond, which in

turn increases the number of aerobic bacteria. These bacteria feed on organic matter such

as decomposing plants and reduce the amount of excess nutrients released into the water.

Algal growth may also be prevented by steepening the sides of the pond during construction.

A slope with a 3 to 1 decline helps to eliminate shallow areas that can be penetrated by sunlight,

and can discourage the growth of algae.