For a pond or lake owner, there is nothing more terrible than having a sudden mass extinction of aquatic life—otherwise known as a Fish Kill.

Fish kills come in many shapes and forms—sometimes big fish die, sometimes small fish die, other times all fish meet the same demise. Some fish kills are limited to a particularly sensitive species of fish, others do not discriminate and affect all fish (including the big game fish you keep fishing for).

A fish kill can be as small as 10-20 fish or as large as 10-20,000—and once fish begin to die, it’s generally too late to remedy the situation. The only way to thwart the fish kill phenomenon is prevention.

Before we can prevent fish kills, we must understand the six possible causes behind them:

1. Oxygen Depletion

Oxygen depletion is the most common cause of fish kills. Oxygen must be present in the water for fish to breathe—an oxygen level of 4-5 parts per million is recommended for healthy fish.

When oxygen levels dip down to 2-3ppm, fish become stressed. Fish swimming near the surface, sometimes gulping the air, is a common symptom of this stage.

Large fish are the first to die in an oxygen depletion fish kill, followed by the smaller fish.  Fish kills of this sort often happen overnight or in the early morning—and typically occur in a matter of hours.

2. Large Plant or Algae Die-Off

When a body of water rife with plants and algae suddenly receives less sunlight or receives algaecides and herbicides, large die-offs can occur. The resulting decaying matter wicks oxygen out of the water, suffocating your fish.

As a rule of thumb, if your pond has more than a 20% covering of algae or surface plants, avoid algaecides and herbicides and get oxygen into the water as quickly as possible (see solutions).

3. Turnover

Stagnant water tends to migrate into distinct layers—like a layer cake. Fish typically reside in the layers near the surface where they enjoy warmer water and higher dissolved oxygen.

The layer at the bottom is like a fish no-man’s-land as it is generally is colder, has little or no oxygen, and is filled with accumulating toxic gasses that are trapped by the layer differences.

In the spring and fall (and sometimes more often if the weather conditions are just right) these layers mix, sucking all the oxygen out of the water and introducing toxic gasses to the fish. If severe enough, turnover can easily cause a mass fish kill.

4. Surface Freeze

When the surface freezes, the ice acts just like the temperature difference mentioned in #3. Gasses poisonous to the fish build up, and can sometimes wipe out entire populations.

5. Toxins and Chemicals

If pesticides or other harmful chemicals run into your pond, it can obviously have a damaging affect on any life within it.

Sometimes the application of herbicides or algaecides can lead to fish kills, as the chemicals is lethal to all sorts of aquatic life.

6. Disease

Disease affects all life forms at some point or another, and it’s hard to prevent. The symptoms of disease, however, are often less severe than most fish kills and happen gradually over time (rather than over the course of a few hours, like a normal fish kill).

Disease generally affects only one species of fish, seldom killing all of them, and rarely do they occur on a mass fish-kill scale.

Solution

With its patented Double Bubble™ Technology, the MARS Aeration System will prevent almost all fish kills by targeting its main causes. The MARS simultaneously:

• Adds  oxygen to the water keeping the water fresh and fish happy
• Mixes the layers to expand the fish habitat and break up toxic gasses
• Prevents excess Algae from taking over and wicking out oxygen
• Allows You to Avoid the Application of Chemicals that can harm fish

Visit the Eco-Friendly Aeration page to learn more abouy the benefits of the MARS!

Do you dread changes in the wind because the smell of your pond or lake wafts into your home? Do you avoid gatherings or cookouts down by the water because of its unappealing odor? You’re not alone.

We’ve all walked past stagnant, a stinking pond and lake at some point in our life (and a lot of times we wish we hadn’t!), but have you ever wondered where that smell is coming from…or how to stop it?

Let’s first look at the causes of pond or lake odor. The smell you notice comes primarily from three sources:

1. Rotting Plants, Fish, and other Organic Matter:

When something rots, it smells—this is a simple fact of life that has us routinely taking out the trash and hunting through the refrigerator for foreign smells.

But, what occurs in lakes and ponds that make the odor so pervasive? It’s the lack of oxygen.Many rotting things in your pond are digested by aerobic (oxygen breathing) bacteria, and this occurs both quickly and largely without odor.

If given enough oxygen, these hungry little bacteria will clean all the odors and decaying matter out of your pond. Unfortunately, this is not what happens in most ponds—stagnant water instead has the tendency to develop into distinct temperature layers.

Water warmed by the sun remains toward the surface, and cooler, denser water stays on the bottom. Being sealed in by the upper, warmer layer, the bottom layer receives no oxygen. Eventually fish and bacteria use up all the available oxygen in this area, and this is when things get bad.

What happens is that all inanimate organic matter (dead fish, leaves, grass clippings, sticks, fish waste, dead plants) sink to the oxygen-less, or anoxic, area at the bottom of the pond. Here, the only breakdown and digestion that occurs is done by anaerobic (not oxygen breathing) bacteria.

Not only are these bacteria seventeen times slower at breaking down organic matter than aerobic bacteria, but they also produce nasty smelling pond odors as a byproduct. These odors include the rotten egg-like hydrogen sulfide, methane, and ammonia.

Ever see bubbles rise to and burst on the surface of your pond? That’s likely anaerobic bacteria, releasing their pungent pond odor byproducts.

2. Turnover:

Pond or lake turnover is often a reason why your water occasionally smells really bad. It occurs at least twice a year in the spring and fall (sometimes more if there are heavy rainstorms) where the upper and lower levels of your water body mix together.

The resulting solution is low in oxygen and high in noxious gasses (and this very dangerous for fish and can result in a massive fish kill). On top of this, all of the bad odors and decaying material once trapped at the bottom are mixed into the water column all at once, making your water smell quite awful.

3. Odor Producing Algae:

Certain kinds of algae simply smell bad. Ponds with heavy concentrations of cyanobacteria or chara algae, for example, will emit a musty, earthy odor.

So not only will your pond look bad because of the large algal blooms, but it also smells bad because of the algae!

The Solution to Lake and Pond Odors:

Now let’s look at the solution to pond and lake odors. The fix for pond and lake odors is Eco-Friendly Aeration with the MARS System, which targets the causes of odors by doing the following things:

• Oxygenating ALL areas of the water column so aerobic bacteria get to the organic matter and  do its work without odors

• Mixing the entire pond from top to bottom, avoiding layering and stopping the harmful and odor producing effects of turnover

• Prevent algae by breaking down the organic matter before algae has the chance to use it to fuel its growth

The MARS Aerator’s patented Double Bubble™ Technology both mixes & aerates your pond—keeping it healthy, clear, and most importantly, odor free!