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What is Turbidity?

What is Turbidity?

Is your pond water always muddy with a murky brown appearance? If so, you may be dealing with turbidity. What is turbidity, and how can you fix it?

Turbidity Explained

Turbidity is the measure of relative clarity of a liquid and how much light can pass through a water sample. The term is used to describe ponds in which particulates are suspended for a prolonged period, causing water to look muddy or cloudy. Turbidity is most commonly seen in ponds with soft clay bottoms or in ponds where erosion and runoff are common factors.

A pond is considered turbid if you are unable to see past the top two feet of water. Beyond an unattractive appearance, turbidity blocks sunlight and lowers oxygen in the water, which can harm aquatic life in the pond.

What Causes Turbidity?

Many things. In some areas, it may just be the chemical makeup of the water and soil that just don’t mix well. In some ponds, very fine clay particles never settle. Weather can also affect pond clarity, especially storms with heavy rain and wind.

In other ponds, turbidity may be caused by livestock or wildlife that are causing erosion and stirring the water. Cattle enjoy a good dip and ponds are a great water source, but cattle wandering in the water can be a direct cause of an unsettled pond. A pond can get stirred up by muskrats, large flocks of ducks or geese, catfish, buffalo fish, carp, and other creatures that root along the bottom, creating constant re-suspension of the sediment.

Excessive nutrients and phosphates can also lead to water clarity issues. Phosphates come into a pond or lake from decaying organic matter and storm runoff, which carries fertilizers and other contaminants. There is no one cause of turbid water, which makes it a difficult problem to resolve. In many cases there is nothing a pond owner can do to help your water clarity, but there are some measures that may help.

How to Clear a Turbid Pond

Doing a jar test is an important step in determining what is causing your turbid pond and whether the sediment will settle when undisturbed for a time. It’s simple to do. Take a clear glass jar, dunk it into your pond, fill it with water, cap it, and keep it in the dark. We recommend letting your jar sit for about a week to see the full results. Observe the water from the top down as well as from the side.

Control Phosphates: If during the jar test your water remains murky and cloudy it may be a sign of high levels of phosphates. Farm runoff, lawn fertilizers, and animal waste are among the most significant contributors to extremely high levels of phosphates. The good news, treatment is easy. Airmax EcoBoost PRx, is a highly effective, all-natural phosphate binder that works within the water column to clear up cloudy or murky water and restore your water quality.

Control Environment Factors: If the water clears during the jar test, your pond is turbid because of environmental factors. You will need to determine what those factors are and if you can control them. If you have determined that your murky pond is due to excessive erosion, you can plant grasses and trees to control erosion, wind, and storm runoff. If creatures are causing problems, you can remove or adjust livestock access, add predator fish to control an overpopulation of catfish, buffalo fish, or carp, and keep undesirable wildlife away. There is only so much you can do to control animals in and around your pond. For example, catfish and carp root around the lake floor, constantly stirring up debris. It’s their nature. The only true solution is to remove the fish entirely.

Add Gravel & Bottom-Growing Vegetation: If you have determined that suspended clay is causing turbidity in your pond, consider adding stones or pea-grave to the bottom. Allow Chara and other bottom-growing plants to root. The addition of gravel and plants will help settle your pond bottom and clear the water. If you have bottom-feeders such as catfish or carp, however, they will keep clay particles in suspension.

A Few Final Tips:

Contact your local Department of Natural Resources for information on soil and water issues in your area. Ask if there are water testing opportunities. If there is an agricultural extension office near you, they might have additional resources and testing options available to you.

DO add aeration to your pond. Turbid ponds have lower oxygen saturation, and plant and animal life will suffer as a result. Adding oxygen won’t clear your turbid pond, but it will boost beneficial bacterial activity and increase water clarity.

DO use the Airmax ClearPAC after settling pond to clean, clear, and balance your pond and reduce excess nutrients that may be left behind from a formerly turbid environment.

DON’T use hay or straw. Though this is a treatment trend, it is temporary at best. Adding straw or hay increases your nutrient load and may lead to harmful algae growth. There is no scientific evidence to support the use of hay for settling or clearing a pond.

DON’T treat too fast, rapid adjustments can negatively affect oxygen saturation and kill fish.

In some ponds, even the best treatment may be temporary. Turbidity is a challenging problem to overcome. However, if you have worked to address the root cause of your turbidity and taken steps to proactively treat your pond, your treatment will be more effective.