I realize that winter is officially ending for the year, however I came across this video on youtube and thought it would be great content for the blog. Here it is an instructional video on how to winterize an EasyPro Pond Pump and EasyPro Skimmer:
Studies at the University of Florida indicate that sediment or sludge build up can accumulate at a rate of 1 to 5 inches or 2.5 to 12cm per year in temperate climates. While in tropical climates the rate increases to 3 to 8 inches, or 6 to 16 cm per year all depending on the level of nutrient loading.
At a mid point accumulation rate of 3 inches or 7cm per year, a one surface acre or a 4000 square meter lake will lose 80,000 gallons or 300 cubic meters of water storage capacity in a single year. Imagine the impact on an irrigation storage basin over the course of ten, twenty or fifty years. Sludge build up can gradually occur, robbing any lake or irrigation basin of it’s capacity to store water.
The second most common source of nutrients is runoff from surrounding turf areas as well as roads, farms and other outlying areas. The USGA reports that up to 4% of the fertilizers applied to areas adjacent to ponds and lakes may eventually runoff into the ponds, this runoff of fertilizers into ponds is known as nutrient loading. Consider that a golf course may apply up to sixteen tons of fertilizer in a year the possibility for a half ton of fertilizer to runoff into the lakes or drainage basins exists. Leaves, grass clippings, and other materials will also runoff into the lakes, placing additional burdens on the pond’s natural clean up processes. Ponds and lakes often act as Mother Nature’s “garbage cans.”
Nutrient loading can be very high in waters adjacent to green areas or turf grass. As the nutrient levels in the pond increase, the rate of plant growth will increase as well. The following chart shows the impact that nutrient levels can have on aquatic plants and algae.
A case study presented by the North American Lake Management Society (NALMS) suggests that the algae can absorb over 1mg\L of phosphorus and over 2.5mg\L of nitrogen. Nutrients do have a significant impact on algae and aquatic weed growth, increased nutrient levels usually mean increased plant levels.
Nutrient is also added to our lakes and ponds through inlet waters. This inlet water can come from effluent sewage, wastewater treatment plants and leeching from septic systems. Often inlet waters have minimal oxygen and are loaded with phosphorus, an indication of excess phosphorus is foaming water.
The third essential factor in lake and pond ecology is the role oxygen plays. Oxygen is important to all forms of life in the lake, after all how long can we live without air? Oxygen supports the food chain in a lake or pond, a healthy ecosystem in a lake contains a wide variety of plants and animals including a natural mechanism to biodegrade organic nutrients. The bottom of the food chain consists of microscopic algae which are consumed by slightly larger zooplankton. Each level of consumer transfers a small fraction of the energy the lake receives up the food chain to the next level of consumer. This means that a few sport fish depend on a much larger supply of smaller fish, and in turn the smaller fish depend on a large base of plants and algae. This large mass of plants and algae require an even larger amount of nutrient to grow, a healthy food chain can pull a tremendous amount of nutrient out of the water. Oxygen supports this entire system.
Natural decomposition processes in the aquatic ecosystem are oxygen dependent. Aerobic digestion is a fast and efficient way of breaking down nutrients. Moreover, an abundant supply of dissolved oxygen supports the oxidation and other chemical processes that help keep the lake in ecological balance.
How is a lake supplied with oxygen? From several sources but primarily through photosynthesis, wave and wind action. Aquatic plants and algae produce large amounts of oxygen through the light process of photosynthesis. This is an important source of oxygen in most ponds especially older, eutrophic ponds. At night plants become oxygen consumers in the dark process of photosynthesis and produce carbon dioxide. The other significant oxygen producer is the oxygen transfer created by wave and wind action. The surface area of the lake is increased by surface waves or ripples caused by wind or other means, this wave action created by the wind creates additional circulation and partially breaks down thermal stratification. Surface waters that have direct contact with the air will be oxygenated through diffusion. And finally, as the rain passes through the atmosphere it picks up free oxygen and deposits it in a dissolved state when it strikes the surface waters of the pond.
Oxygen depletion or stress situations occur for different reasons. Whenever oxygen levels fall below 3 to 4 PPM or mg\L an oxygen stress will occur. Typical situations when this will happen are:
The most immediate reactions to oxygen depletion would be fish kills or odors. Long term issues include nutrient build up, sludge accumulation, and a chemical imbalance in the lake.
Nature has provided a clean up process that will metabolize or decompose excess nutrients. This process is called organic digestion. Two types of naturally occurring bacteria are present in all lakes and ponds, aerobic and anaerobic. The bacteria in the water will work to break down the nutrient load by feeding on the organic nutrients and digesting it into non-organic compounds that algae and aquatic plants can not readily use for food.
The most effective of these bacteria are aerobic bacteria. Aerobic bacteria only live in the presence of oxygen and they metabolize or break down nutrients respiring or consuming oxygen in the process. They are very efficient, breaking down organic nutrients, carbon dioxide and other materials and are roughly seven times faster in organic digestion than anaerobic bacteria.
Anaerobic bacteria also break down organic nutrient and exists in pond water and soils that are oxygen deficient. They are not as effective as aerobic bacteria in the digestion of organic wastes and allow soluble organic nutrients to re-cycle into the water column. Noxious by-products such as methane, ammonia and hydrogen sulfide are created by anaerobic decomposition. In general, any foul smelling waters can be assumed to be anoxic or oxygen deficient.
Oxidation is a chemical process that is dependent on oxygen. Oxygen has a positive molecular charge, as an oxygen molecule affixes itself to a particle in the water it then starts to oxidize or break down the molecular bonds which hold the particle together. In addition, the positive molecular charge of the oxygen molecule will create an attraction and pull several small particles together, a process known as coagulation. These heavier, coagulated particles now precipitate, or fall out of suspension. In this process soluble substances like phosphorus and iron become insoluble and unavailable for use by aquatic vegetation. A balanced aquatic ecosystem contains a fairly low population of algae and aquatic weeds as well as other forms of nutrient. Aerobic bacteria feed on the organic nutrients and digest it into non-organic compounds that algae and aquatic plants can not use as readily for food.
Simple water quality tests will indicate the nutrient levels and other valuable information in regards to lakes and ponds. These tests typically monitor dissolved oxygen, biological oxygen demand, alkalinity, pH, phosphorus, nitrogen, and fecal coliform in some situations. Dissolved oxygen is described in either parts per million or milligrams per liter. Biological Oxygen Demand is referred to as BOD. The chart indicates the appropriate levels for lakes and ponds. This testing can be completed by most water testing laboratories and water testing is important for a complete understanding of the water you are trying to manage.
Let’s put it all together…
Let’s take a look at how all of these mechanisms interact to make the lake behave the way it does. As a lake ages the level of nutrient rises, this is due to an increase in runoff, organic bottom sediment, or fertilizer used in the surrounding area, and in the amount of algae and aquatic weed growth. As these weeds grow and die they sink to the bottom of the pond to decompose, this will result in a sudden increase in the activity and population of aerobic bacteria due to the large food supply. The depth of the lake will decrease as the biomass at the lake bottom accumulates. Aerobic bacteria will use a large amount of oxygen as they digest organic waste, with primary source of oxygen in the pond coming through surface contact, rainfall and plant photosynthesis.
Due to thermal stratification the top and bottom layers of the pond will not mix and the needed oxygen can not get down to the lake bottom to support aerobic digestion. This will cause an oxygen depletion problem in the lower layers of the lake and may result in nutrient cycling, fish kills and foul odors caused by anaerobic digestion. The problem is caused by poor water quality, that is excessive nutrient levels, poor circulation and low oxygen levels.
Balance is critical to the aquatic ecosystem. A healthy lake contains balanced amounts of oxygen, nutrients, and temperature.
As pond owners & managers, it’s important that we understand the factors that impact the delicate balance of a pond. The three most significant factors to the lake manager are:
1. Light and Temperature
2. Nutrients
3. Oxygen
Sunlight is of major significance to pond dynamics as it’s the primary source of energy. Most of the energy that controls the metabolism of a pond or lake comes directly from the solar energy utilized in photosynthesis. Photosynthesis will occur only in the euphotic zone or upper layer of the pond, this is the area in the water column that sunlight is able to penetrate. Shallow bodies of water less than 9ft/3m in depth more commonly experience problems such as bottom-rooted weeds or benthic algae.
Thermal Stratification is a term meaning temperature layering. As the sun shines on a pond it warms the surface water, this water becomes lighter than the cooler, denser waters which are trapped at the pond’s bottom. As the hot summer season progresses the difference in temperature between the warm surface waters and the colder bottom waters grows. As a result the water becomes stratified or separated into layers with the top and bottom layers of the lake do not mix with each other. The area between the warm and cold layers, called the thermocline or metalimnion, can act as a physical barrier preventing any vertical mixing in the pond or lake. And, remember warm surface waters encourage algae growth.
Have you ever experienced this phenomenon when diving into a pool or lake and noticed that the water is colder at the bottom than on the surface?
Thermal stratification impacts the water quality in a lake primarily because of its effect on dissolved oxygen levels, the way we measure how water holds oxygen. Warm water has a diminished capacity to hold oxygen, in fact water at 52 degrees Fahrenheit or 11 degrees Celsius can hold over 40% more oxygen than water at 80 degrees Fahrenheit or 27 degrees Celsius. As water temperature increases, the water’s capacity to hold oxygen decreases.
Dissolved oxygen in a lake comes primarily from photosynthesis and wave/wind action. During stratification, bottom waters are removed from both of these sources and an anoxic or no oxygen condition occurs. Aquatic organisms require oxygen to survive, in its absence organisms must move from the anoxic area or die. Anoxic bottom waters lose most if not all of the zooplankton and aerobic bacteria necessary for efficient and effective digestion, while less effective more pollutant tolerant forms of anaerobic bacteria will develop.
The lack of dissolved oxygen sets in motion a series of chemical reactions that further reduce water quality: sulfide is converted to hydrogen sulfide, insoluble iron is converted to soluble forms, suspended solids increase and a severe decrease in the decomposition of waste materials on the pond bottom will occur.
Thermal stratification occurs in a seasonal cycle with the thermocline becoming more severe in late summer and late winter. Lakes and ponds in warmer weather regions experience a shorter annual cycle spending more time in late Summer and early Fall conditions.
Shallow lakes offer the water manager an even greater challenge. Shallow ponds less than 6ft/2m in depth tend to be very warm allowing for the entire water column to be productive with weed and algae growth. These types of lakes need extra consideration when determining the correct water management solution.
The second essential factor in our lake management discussion is the impact of nutrients on the aquatic ecosystem. There is a direct correlation in the level of available nutrients and the populations of algae and aquatic weeds.
To gain a deeper knowledge it is important to understand the sources of nutrients, how the nutrients are absorbed and broken down, and the impact nutrients can have on water chemistry. In fact a diagnosis of a pond’s chemical make up can help you design a preventative program for a problem pond.
We need to consider the way that organic nutrients are accumulated and digested in the pond. An organic nutrient is a carbon based compound essential to the life of a plant. In lake ecology the macro nutrients we specifically talk of are phosphorus and nitrogen. In fact, phosphorus has been identified as the single greatest contributor to aquatic plant growth, remember that one gram of phosphorous will produce one hundred grams of algal biomass. As the nutrient level in the water increases so does aquatic plant and weed growth, this leads to severe problems from an environmental and aesthetic viewpoint.
It is beneficial to try to identify the sources of nutrient coming into the pond. The three most common sources are bottom silt and dead vegetation in the lake, runoff water from surrounding turf areas, and the sources of incoming water.
Vegetative life in the lake and sediment at the lake bottom are the primary sources of nutrient. Although they only have a two-week life cycle, blue-green algae can experience cell division and double their population as often as every 20 minutes. At the end of the cycle, the plants simply die and begin to sink to the lake’s bottom, adding to the biomass, or total amount of biological material in the pond. This adds to the “aquatic compost pile” at the benthic zone or bottom. The layer of dead plant material acts as nutrient for future algae and aquatic weed blooms, a phenomena called nutrient cycling. Nutrient cycling creates additional demands on the available oxygen in the hypolimnion, or bottom, and creates a stress situation.
Lakes and ponds evolve through a natural aging process. Under natural conditions this process takes a very long time.
Cultural eutrophication, which is the acceleration of the aging process through human inputs, speeds up this aging process at an exponential rate. These human inputs include erosion, chemicals, fertilizers, waste runoff, leaky septic systems and more. The greater the level of the input the faster the lake or pond ages.
Chances are that the pond in your backyard is man-made. Many times these ponds are poorly designed, may have artificial water tables, and most are so shallow that within a few short years they pass from oligotrophic (new stage) to eutrophic (old stage).
Excessive runoff accelerates the aging process of a pond or lake exponentially. Special attention and management programs are necessary to overcome these effects of aging and keep these ponds and lakes productive and aesthetically pleasing.
Were you able to identify which categories your lakes are in? This is one of the first steps in creating a management program custom fit for your application.
We can divide the lake into regions based on location within the water body. Both the shape of the basin, morphometry , and the shoreline characteristics, morphology, have significant importance to the lake manager.
Inside these lake regions there are zones which have tremendous influence over water quality and our approach to management. These zones include the littoral, limnetic, euphotic, and benthic zones. Let’s take a closer look at these regions.
Morphometry and morphology have significant influence over mixing in the basin. Both vertical and horizontal circulation are important in creating and maintaining a balanced ecosystem.
Morphometry, or lake shape, has tremendous influence over horizontal mixing. Long narrow channels or canals often experience water quality management problems. Isolated peninsulas can create physical barriers to mixing and, water quality issues can more easily occur.
Morphology, or the shoreline characteristics of a lake, has significant impact over vertical mixing and plant populations.Different plants thrive at different depths.
For a more in-depth review of morphology we must begin by exploring specific shoreline characteristics.
First, the littoral zone is the region of the pond sloping from the shore out to the area of open water. It is the interface between the drainage basin and the open water, most generally the area where sunlight will penetrate to the bottom of the pond. The size of the littoral zone is dependent upon pond depth, clarity and wave action. Sunlight, wave action and the lake bottom have a great influence over this zone. Typically, this is the most challenging region of the pond to manage.
You will often see a ring of plants around the shoreline in the littoral zone. The variety and type of these plants are dependent upon depth. A variety of algae, including filamentous found in the littoral zone, will typically make up 90% of the species found in the lake. Algae in the littoral zone are often attached to macrophytes, which are emergent rooted aquatic plants such as rushes and reeds, and they thrive in this zone. Algae and macrophytes make excellent habitat for natural clean up tools like micro flora and zooplankton. Zooplankton are microscopic animals like protozoan, micro crustaceans, rotifers and larger invertebrates such as: aquatic worms, crayfish, insect larvae, and fish.
The second region of review is the limnetic zone, or open water zone. This is the area in the lake that starts at the intersection of the littoral zone and extends out into open areas of the pond. Shore and bottom lake areas will tend to have less influence in this lake region. Planktonic algae, water lilies, submerged pondweed, zooplankton, invertebrates and fish are commonly found in the open water zone. This lake region is typically easier to manage.
The third region for review is the upper, well illuminated layer of the water – or epilimnion. This is the area where photosynthesis by algae and other aquatic plants occurs.
The water column is the vertical column of water contained in the pond. This term is often used when discussing lake characteristics such as oxygen levels, temperature and nutrient content.
The fourth region for review is the euphotic zone or photozone area. This is the upper layer of the pond where sunlight can penetrate to promote the growth of green plants. We’ll review the importance of light to the aquatic ecosystem in just a short while.
Finally, the benthic zone is the area at the bottom of a pond or lake. The benthic zone is comprised of sediment and soil and usually has a high demand for dissolved oxygen.
The littoral zone is the shoreline area where nutrients will runoff into the water. The shallow nature of this zone and the fact that most nutrients will enter the basin through the littoral zone make it the most difficult area in the lake to manage. The limnetic or open water zone is deeper and easier to manage, while the euphotic zone is the region of the water column that is lit by the sun. Depending on turbidity, most of the lakes we encounter have euphotic zones that extend anywhere from 80% to 100% of the water column. And the benthic zone is the nutrient enriched, oxygen starved bottom layer of the lake.
A balanced pond management program will take all of these zones and regions into account and use each to help achieve ecological balance.
A pond in ecological balance is a healthy, dynamic ecosystem that is aging at a very slow rate where fish and other forms of aquatic wildlife are present, and there is an absence of foul odors and algae blooms. As nutrients enter the ecosystem they are either absorbed by the aquatic plants or metabolized by aerobic bacteria. There are safe levels of oxygen present in all regions of the lake with a minimum of 4 PPM or mg\l. Oxygen is added to the pond or lake from wave and wind action, the light side of the photosynthesis process, and rain. It’s a healthy, balanced ecosystem. Mother Nature has provided the necessary clean up mechanisms to keep the pond in balance.
However, this balance is a delicate one. Typically there is an influx of nutrients, as aerobic bacteria respire and consume oxygen they will metabolize nutrients. This process keeps the available nutrients at a healthy level and everything is fine until a hot, humid, cloudy day occurs when the planktonic algae doesn’t photosynthesize and create oxygen or the first long, hot night when oxygen demand soars.
In these scenarios there are no oxygen producers but there are many oxygen consumers, especially in stratified waters where all the demand for oxygen can’t be met. We experience an oxygen stress and in turn a fish kill where the lake then turns anoxic or anaerobic. The limiting factor is oxygen, while the fish kill isn’t the first indicator that there is a problem it’s usually the most dramatic and understandable one.
Imagine two ponds that are side by side, one is fresh, clean and healthy an asset to the property, while the other is dirty, weed-infested and creates odors. Why? Every lake is a unique ecosystem, and unfortunately there are no magical cures for lake problems. This is why it is essential for you to understand the causes of problems as well as the effects.
By increasing your understanding you’ll be able to develop a balanced management and prevention programs for your ponds. As a pond owner, greens keeper or property management professional you should be well aware of your responsibilities and your ability to have significant positive impacts on the environment.
We’ll be reviewing pond dynamics. This includes types of ponds, regions of the pond, and the importance of establishing and maintaining an ecological balance.
In order to design and put into practice preventative water quality management programs it is essential to have a firm understanding of the causes of water quality problems.
We’ll review the effects of poor water quality and the related costs to the property owner or manager, as well as focusing on crafting cause-oriented solutions, designing programs to put your pond in ecological balance and preventing nuisance problems in the future.
Knowing the type of pond you are managing will help you to establish a benchmark for the typical problems you might expect and the management programs you will be able to enact. As you review the three basic types of ponds, be sure to do a quick inventory on the pond you own. Which category does it fit in?
Ponds are generally classified into one of these three categories:
1. Oligotrophic (or new)
2. Mesotrophic (or middle aged)
3. Eutrophic (or old)
The age of the lake and the design of the lake are two critical factors we must consider.
Each pond has zones or regions and it is essential that the pond owner be aware of these zones and use them in maintaining an ecological balance in the pond. A pond that is in balance is a healthy lake, aging at a slow rate.
Oligotrophic ponds are clear, cold ponds with low nutrient levels and few macrophytes or plants. Geologically speaking, these are “new ponds.” Oligotrophic or new ponds have very low levels of phosphorus, usually less than .001mg\l and there is little or no algae present.
Mesotrophic ponds tend to have intermediate levels of nutrients and macrophytes or plants and could be considered “middle aged ponds.” These ponds have higher levels of phosphorus and experience some weed and algae problems.
Eutrophic ponds are characterized by high nutrient levels, turbid water, and large algae and macrophyte plant populations. Phosphorus levels can be in the range of
1mg\l. Considering that one gram of phosphorus will produce 100 grams of algal biomass, eutrophic lakes contain high algae populations.
Ponds which remain muddy for extended periods do not produce quality fishing. Muddy water shades out sunlight necessary for the growth and survival of fish food organisms.
Muddy water is mainly caused by unvegetated watersheds; water entering the pond carries suspended clay silt particles. Once vegetation problems are solved, so are most muddy water problems. If water remains muddy after revegetation of the watershed, it can be cleared up using several methods:
1. Apply 7 to 10 bales of hay per acre at 3 week intervals until the problem is solved. Do not use this treatment during the summer if fish are already stocked because of the danger of oxygen depletion.
2. Add 5 pounds of commercial alum crystals per acre foot. Higher rates may be required, but alum is acidic and high treatment rates in low alkalinity waters may kill fish.
3. Apply 75 to 100 pounds of cottonseed meal with 25 pounds of normal superphosphate per acre at 2 o 3 week intervals.
4. Apply gypsum (land plaster) at 300 to 500 pounds per surface acre.
These methods are temporary solutions. The source of turbidity must be eliminated as the most effective and long lasting remedy for muddy water.
Fertilization increases the capacity of a pond to produce fish. Nutrients provided from fertilizer increase production of microscopic plants (phytoplankton) that serve as food for microscopic animals (zooplankton) and aquatic insects. An abundance of these small creatures gives ponds a green color and is called a “plankton bloom.” Plankton and insects serve as food for bream which are eaten by bass. Fertilization increases the production of natural fish food organisms in ponds. The result is greater fish production and better fishing.
Proper use of fertilizer can increase fish yields two to five times. Fish are easier to catch in fertilized ponds because the cloudiness of the plankton limits their vision, causing them to be less wary. Plankton blooms also reduce light penetration to pond bottoms, preventing growth of troublesome aquatic weeds. Most ponds will respond to a proper fertilization program. However, muddy ponds and ponds with excessive amounts of water flushing through cannot be fertilized effectively. Ponds with soft, acid water may need to be limed before fertilization may be effective.
Not all ponds need to be fertilized. Soils in some areas are high in natural fertility and support excellent fish production without supplemental fertilization. Little or no fertilizer may be needed in ponds receiving runoff from well managed pastures because of nutrients from manure. Large unfertilized ponds fished by only a few people may produce excellent fishing. Heavily fished ponds should be fertilized for best results.
No Pond should be allowed to remain clear, Excessively clear ponds should be fertilized to produce a bloom if only to control aquatic weeds. Fertilizers suitable for farm pond use are available in liquid or granules and are superior in promoting phytoplankton growth in ponds. Granular fertilizers, however, may be more readily available than liquids in some areas.
Fertilization should begin during the first warm weather in Spring when temperatures stabilize in the 60s and continue until the water cools in the fall. Applications should be made every two weeks until the water begins to turn a light shade of green with growing plankton. The plankton should become dense enough so that a white disk cannot be seen at a depth of 18 inches. The bottom of bleach bottle attached to a yard stick works well for checking plankton density in this way. After the desired color is reached, continue applications at monthly intervals or whenever the water clears enough that the disk becomes visible again. Additional fertilizer applications are not necessary unless the pond begins to clear. Disk visibility limited to 6 inches or less, where no muddy water is present, may indicate a problem with over-fertilization.
Ponds with soft, acid water may not respond to fertilizer. If the water does not turn green after six weeks of fertilization, then liming may be necessary. Ponds with waters of less than 20 mg/l of total alkalinity normally need lime. The lower the alkalinity level, the better the pond will respond to liming. Applying agricultural limestone ( i.e. hydrated lime) will increase water hardness and alkalinity and decrease acidity. This will make the fertilizer more effective.
Once low alkalinity levels are determined you are ready. There are many methods of adding limestone and many different opinions of which way is best depending on who it is that you ask. We have found the easiest way to instruct home owners on liming a pond is to get one or two 50 lbs. sacks of hydrated lime, depending on pond size, from your local agricultural supply house. Begin mixing the lime in a 5 lbs. bucket with water until you get a substance that is the same consistency of a chocolate malt. Once that is accomplished dump the bucket into the pond. It may take several buckets to go through one 50 lb. bag. If you have an aerator in the pond it will help mix the lime really well.
If you have benefited from this resource please visit our main site: Living Water Aeration
Like all green plants, phytoplankton produce oxygen during the daylight hours as a by-product of photosynthesis. This is usually a major source of oxygen in fish ponds. In darkness, however, all plants consume oxygen, including phytoplankton. Blooms in natural water bodies or fish ponds normally produce much more oxygen in the daylight hours than they consume during the night, but some situations occur which reduce the amount of oxygen a bloom produces without reducing its nighttime oxygen consumption.
Trace minerals or nutrients needed by the algal bloom are occasionally used up. This usually results in some, or occasionally all of the phytoplankton dying back temporarily. This is probably the most common cause of phytoplankton die-offs, especially for heavy blooms with competition for light and nutrients. When a large portion of the bloom dies off at once, bacterial decomposition and the loss of normal oxygen production can lead to oxygen depletion and fish kills. Pond water generally changes from a deep gren to black, gray, brown or clear after a phytoplankton die-off.
Blooms respond to changes in the weather. Photosynthesis slows down under cloudy conditions and as a result oxygen production decreases. Extremely calm days may also reduce photosynthesis and oxygen production, even under sunny conditions, by preventing phytoplankton in the middle layers of the pond from mixing near the brighter surface. In summer, oxygen problems may arise because of a simple physical property of water. The warmer the water, the less dissolved oxygen it can hold. When a dense bloom produces a surplus of oxygen on a summer afternoon, the oxygen will not stay in solution and escapes into the atmosphere. During the night, the bloom attempts to take more oxygen out of the water than what remains from daytime photosynthesis. When this occurs, dissolved oxygen levels approach zero. Fish begin to suffocate in the pond and aeration must be applied to meet the demand for oxygen and prevent fish losses,
Many ponds also experience problems in early spring. As the water warms and the amount of sunlight increases, algae species which predominated in the bloom during the winter die back, and other species more suited to summer conditions multiply and replace them. When this process proceeds gradually, conditions remain fairly stable. Occasionally, however, the winter bloom dies off abruptly and insufficient oxygen levels may occur for several days.
This type of oxygen depletion may kill some fish directly or cause sufficient stress or weaken their immune systems. Bacterial infections usually occur within the next several days to two weeks. Various signs, such as color and odor changes or a buildup of foam on the down-wind bank can sometimes be useful in anticipating when a winter bloom will die back.
-Is your Pond 6ft. in depth or deeper?
-Have you seen your fish gasping for oxygen at the top of your pond?
-Are you having unsightly algae problems in your pond?
-Does your pond appear to be stagnate and lifeless?
If you have answered yes to any of the above questions or want to improve your water quality — read this info!
“Aeration” is the term that we use to mean adding air to the water. Because air contains 20% oxygen aeration adds oxygen to the water. If you have answered yes to any of the questions above your problem may be due to insufficient levels of oxygen in your pond. Ponds that are deeper than 6 ft. simply are not capable of producing significant levels of oxygen at those depths. Below is an illustration that will show you the problem:
Pond with no oxygen needs a pond aerator, pond aeration
The good health of a pond is held in a delicate balance. A pond’s condition deteriorates when its bottom environment cannot support animal life. The bottom is the area that runs out of oxygen first (the bottom is where the most oxygen is used and is the farthest from the surface where it is replenished). The absence of oxygen kill all of the bottom dwelling animals that help keep a pond clean. The loss of these animals (snails, mussels, worms, etc.) will greatly reduce the pond’s ability to clean itself.
Nutrients (fish waste, grass clippings, dead algae, etc.) cause most water quality problems. Nutrients are cleaned from a pond’s bottom by the small bottom dwelling animals mentioned above. When these animals do not exist the nutrients accumulate on the bottom forming a layer of “muck” which serves as fertilizer for weeds and algae. If a pond is allowed to get seriously infested with weeds, herbicide treatment may be the only way to gain control. The idea is to prevent such infestation in the first place. Natural water cleanup through aeration offers preventative maintenance, reducing sediment before more serious problems arise.
a pond without aeration and a pond with pond aeration
Pond Aeration – By pumping compressed air out into a pond or lake bed aerator — an air diffuser that produces tiny air bubbles — the rising air bubbles bring bottom water to the surface where it is exposed to the atmosphere. Large volumes of water thus lose bad gasses to the atmosphere and the water picks up even more oxygen while on the surface
Surface Splashers Vs. Diffused Pond Aeration
Surface Splashers include but are not limited to the following:
* Fountains
* Water Pumps
* Propeller type
-Look at the illustration below and notice how a diffuser will saturate the entire pond with oxygen and not just the surface. Unfortunately , as you can see the surface units expose just surface water to the atmosphere. NOT deep water.
Stagnate water at the bottom of the pond
With a diffused aerator the entire pond receives adequate aeration.
-Fountains are a popular choice when a decorative aerator is desired. Fountains splash the surface of the pond and help control surface algae and duckweed, but do not aerate down to the bottom in deep ponds. They are recommended for ponds with a max depth of 5′ or less, otherwise diffused aeration will always be a more effective means of aeration.
-Diffused pond aeration is the best way to aerate deep ponds. Because the air diffuser lays on the bottom you achieve total pond aeration from top to bottom regardless of depth.
-Diffused aeration systems are the best way to aerate, destratify and create circulation on ponds over 6′ deep. Each system has three basic parts:
-2. an air hose
-3. an air diffuser
-The air compressor sits on shore and pumps air out through the hose to the air diffuser located on the bottom of the pond. The result is thousands of tiny bubbles rushing out of the diffuser to the pond surface, creating circulation and providing aeration. There are several advantages to using diffused pond aeration kits instead of surface aerator:
-1. Electric motor is on shore, not in the water;
-2. Air diffusers lay on the bottom, ensuring aeration of entire pond from bottom to top, regardless of depth size;
-3. With proper sizing, tubing lengths up to 2000′ can be achieved for ponds without electricity nearby.
-Oxygen is most needed at the bottom or deepest part of a pond.
-Surface Splashers can also be a safetey hazard, electric wires need to be ran from your power source out to the motors in the water.
The deeper an air diffuser is located, the more boiling action it will create and a larger area will be aerated. Therefore the deeper your pond the less CFM needed to aerate your pond. 1.5 CFM of air can effectively aerate a 1 Acre pond at a depth of 12′ or deeper. The chart below can be used to determine the size of the compressor that you will need, it is based on a compressor producing 1.5 CFM of air.
Below are the links to several pond aerator kits:
