Why is the water in some reservoirs green? What to do to prevent the pond from blooming
Blooming water in a pond occurs due to the development of phytoplankton. This is what this phenomenon is called because the clear water in a reservoir suddenly acquires a completely saturated color - most often green, but it can be yellowish and even brown.
Typically, blooms begin at a threshold level of algae levels in water bodies. The norm is considered to be an algae concentration ranging from hundreds to thousands of single-celled algae per 1 ml, depending on the size of the cells of individual species.
When the water blooms, the concentration of algae sometimes reaches a million or more cells per 1 ml. They fill the reservoir so densely that a person sees only clusters of single-celled organisms. And their color depends on the species that has entered a state of population explosion.
The question remains why these algae reproduce so rapidly that water is not even visible between their bodies.
In nature, all bodies of water have a constant, balanced composition of substances dissolved in water. The same applies to the species living there - from single-celled organisms to large fish and even birds living on the surface of this water.
An explosion in the number of species never happens just like that. This is always accompanied by changes in environmental conditions. They can relate to any parameter of the life of a reservoir. Changes may occur to:
- temperature conditions;
- chemical composition;
- species composition at the level of any kingdom of living organisms.
All these factors are interconnected with each other. Each of them can become the beginning of a chain of changes that will turn a blue lake into a blooming reservoir. However, there will be no flowers on it: it will be completely covered in mud of one color or another.
How do the above factors work?
What can happen in water, for example, when the temperature changes? Most often, this leads to the death of certain species of organisms that are not adapted to higher water temperatures. Complex food chains and nets may yield several predatory fish.
As a result, herbivorous fish begin to reproduce. This leads to a sharp decrease in the food supply, that is, the number of plants. Herbivorous fish begin to die of starvation. As a result, a large ecological niche is being vacated, formed by a sharp drop in the number of species from several links in the food chain.
This is where the moment of truth comes. Some type of single-celled plant, which previously had a small number because it was slaughtered by competitors, begins to multiply rapidly, filling the entire space of the reservoir. This rapidity does not allow the previous species to recover to the required numbers.
Most often, blooms occur due to eutrophication of water bodies. This translated from ancient Greek means good nutrition. In science, this term describes the process when substances enter a body of water that stimulate the growth of bioproductivity of primary producers, that is, plants and, above all, algae.
Eutrophication can be natural or anthropogenic. An example of the first could be the entry of nitrogen and phosphorus compounds into a reservoir, which lead to an outbreak of algae. As a result, a mountain lake with the purest water turns into a swamp covered with green mud.
Anthropogenic eutrophication is usually associated with the use of mineral fertilizers. Excess of these substances flows into lakes and rivers, creating favorable conditions for a sharp jump in primary bioproductivity.
Changes in the species composition of a reservoir can occur at the level of long trophic chains, similar to the one described above. However, other situations are also possible. For example, a plant species gets into the lake that has not been here before and no one eats it. As a result, this plant (not necessarily an algae) grows rapidly and fills the entire water space. Such plants may also include small multicellular plants - duckweed and salvinia.
The flowering of a pond should not be confused with its overgrowing with large plants such as water hyacinth, lotus, water lily, etc. In this case, the pond parameters do not change. It’s just that there are so many large plants that eventually, in place of the reservoir, first a swampy lowland is formed, and then dry land altogether.
Negative consequences
Typically, eutrophication and subsequent overgrowth with algae and duckweed do not bode well for the ecosystem. It would seem that the more oxygen, the better. In an isolated aquatic ecosystem, everything is different.
Oddly enough, the bloom of water bodies leads to a decrease in the amount of oxygen in the latter. In parallel with algae and other plants, bacteria begin to multiply, and fungi begin to multiply at the bottom. Since there is no one to eat the plants, their dying parts fall to the bottom, where they become food for fungi, bacteria and some surviving invertebrate animals. In addition to fungi, putrefactive bacteria settle on fallen organic matter. As a result of the activity of all these organisms, the amount of oxygen in the water decreases. Plants cannot cope with the excess carbon dioxide released by bacteria and fungi and also die.
As a result, a reservoir that has undergone the process of eutrophication turns into a fetid pit where only anaerobic bacteria can live, whose activity emits the smell of rot and hydrogen sulfide. This is the sad result of the flowering of the reservoir.
Necessary measures
Eutrophication of natural lakes, rivers and even seas is a major environmental problem that is not so easy to solve. It’s a different matter if we are talking about a small pond in the country. Its flowering is a predictable process, since it is in conditions of environmental instability.
What to do if the pride of your site suddenly became covered with mud and quickly began to become waterlogged. There are the following ways to combat this phenomenon:
- 1 Change water. As a rule, this process is labor-intensive, since it requires powerful equipment with which the water can be delivered to its destination. However, when creating such ponds, people usually create a system for providing them with water.
- 2 It is possible to use chemicals that can rid a reservoir not only of an abundance of algae, but also of all living things in general. This action cannot be called environmentally adequate, but a person uses pesticides, which are highly toxic, fortunately, temporary.
- 3 The optimal way out is to try to restore the bio-balance by populating the reservoir with organisms that purify the water. These include hornwort, marsh iris, cattail, etc. Eichornia, also called water hyacinth, perfectly purifies water. However, it grows quickly and can quickly take over the entire reservoir. However, for temperate climate conditions this is not a problem - water hyacinth does not overwinter here. During this time, it must be moved to a warm room. You can also introduce daphnia crustaceans into the pond, which feed specifically on blue-green algae. Mollusks, including bivalves, can be good helpers in cleaning a reservoir. Finally, introduce herbivorous fish in the required quantity
- 4 If the pond is small, then you can simply cover it with a dark cloth for a while. After a few days, most of the duckweed and algae will die. True, this method is only good when you do not have other plants that you specifically cultivate. However, shade can also be created using the plants themselves. If you grow water lilies, egg capsules, and chilims in a pond, which take root in the ground and spread their leaves on the surface of the water, then an outbreak of algae will not occur. Firstly, the leaves of all these plants create a shadow in the water, which will reduce the bioproductivity of bacteria and algae. Secondly, all these plants consume large amounts of minerals, including nitrogen and potassium, so there are simply not enough minerals for the pond to bloom.
Natural lakes, in which all the shallow waters are overgrown with egg capsules, water lilies and other similar plants, have dark, but still always clear water.
The main problems associated with pond maintenance arise from water contamination. You can also keep fish in tap water, but given that chlorine is added to it, which forms acids with water, the water must be left for several days before introducing the fish so that the acid has time to decompose. During the summer heat, water should be added to the pond in small portions; if you add a lot of water at once, this will lead to a change in temperature and an increased chlorine content in the water. When keeping fish in a pond, you need to monitor the acid-base balance.
Why does the water turn green?
The reason for green water is small algae living in the pond. The algae itself does not harm the fish, but it does cause the water to become cloudy. Already two weeks after filling the pond with water, it becomes greenish, this must be dealt with, otherwise the situation will only get worse. Algae multiply especially quickly when the surface of the pond is heated by sunlight and the water contains a lot of carbon dioxide. In the fight against green algae, you need to create unfavorable conditions for them. The situation will be better if the area of the pond is more than 3.5 square meters and there are plants in the pond that shade its surface and absorb carbon dioxide and mineral salts from the water. It is also necessary to regularly clean the water from fallen leaves and food not eaten by the fish.
Even if you follow all the recommendations for cleaning a pond, it is very difficult to fight green algae, since the fish lift silt from the bottom of the pond, and the powerful pump mixes the water too much. The fight against algae becomes very difficult if the area of the pond is too small (less than 3.5 sq.m), if the depth of the pond is less than 45 cm, if there are no plants in the pond. In this case, you need to resort to chemical means of purifying water from algae. It is advisable to use algaecides that are least harmful to fish and plants. There are selective algaecides that provide an effect within 1-4 months. Another type of algaecide binds organic matter and algae, causing it to settle to the bottom of the pond.
All of the listed water purification products allow you to get rid of algae only for a short time. Only a water filter can radically solve the problem.
Weeds
Weeds can spoil the appearance of a pond; in addition, they interfere with the growth of ornamental aquatic plants and make it difficult to view fish. Aquatic weeds include filamentous algae that cling to the bottom and walls of the pond and form balls that float in the water. Filamentous algae or filamentous algae do not form in those ponds where higher plants are planted to bring the pond into a state of equilibrium. On the contrary, there are many of them where filters are installed. It is best to remove filaments with a net, double-horned fork or rake. The forks and rakes need to be turned in the water, thus winding up the algae that needs to be removed from the pond. Plants floating on the surface of the water (duckweed) also clog the pond. They need to be caught from the water in a timely manner before they grow too large. It is also necessary to fight aggressive coastal plants, which, as they grow, begin to crowd out tender plants.
Polluted water
Dirty water is dangerous for fish and plants, although it may be colorless and odorless. Water can become contaminated as a result of rotting leaves of underwater plants, resulting in an oily film forming on the surface of the pond, preventing oxygen from entering the pond. This film must be removed; you can use newspaper, which will absorb it. When dry leaves or dead fish rot, the water turns black. If the water is heavily polluted, it is necessary to pump it out and fill the pond with new water after thoroughly cleaning it. Water must also be pumped out if chemicals (paint, herbicides, etc.) have entered the pond. In small ponds, fish waste gradually accumulates, releasing toxins as it decomposes. A partial water change in the fall and a permanent change will help to cope with this problem. The water is pumped out to a quarter of the total volume, then clean water is added with a thin stream to the usual level.
Muddy water
Muddy brown water, although not dangerous for plants and fish, greatly spoils the appearance of the pond. The reasons for cloudy water are too powerful a pump or turbidity raised by fish from the bottom and from baskets in which plants are planted. Prevention will help to cope with this problem: it is better to cover the tops of the baskets with burlap or fill them with gravel, and install the pump so that it does not create a strong flow of water. Chemicals (flocculants) will help cope with this problem only temporarily, while the flakes that have settled on the bottom of the pond must be removed, but the water will become cloudy again if the main pollutants are not removed.
Acidic or alkaline water
To determine the acidity level of water, you need to use special devices. If the pH level is between 6.5-8.5, then the water is suitable for use. If the level is higher or lower than these values, then plants and fish cannot be grown in such water. At a pH value of 9.0 and above, the water is alkaline, this phenomenon is most often observed when waterproofing a pond from artificial stone or concrete. Therefore, before using the pond, all concrete surfaces must be painted over, and then buffering reagents must be added to the water. Water is acidic if the pH value is 6.0 or less. An acidic environment occurs when water from peat bogs enters the pond. In this case, you need to partially change the water and add limestone to the pond.
Pond cleaning
If the water in the pond is dirty or there is too thick a layer of silt at the bottom, this means that the pond needs to be cleaned. In the spring or summer, riparian and submerged plants are removed from the pond and can be placed in a temporary pond made of plastic or butyl rubber liner. Plants that act as oxygenators and float on the surface of the water are placed in plastic containers filled with water. Then the water from the pond is pumped out. When there is little water left, the fish are taken out with a net and transferred to the tank. After all the water has been pumped out of the pond, the silt is removed from the bottom. It is also necessary to remove dirt from the walls of the pond. The pond is then filled with water again (clean tap water with a small amount of old water added). After filling with water, you can plant the plants again and introduce the fish.
Problems with pond maintenance | Near the Househttp://site/wp-content/uploads/2012/11/IMG_3004-450x233.jpghttp://site/wp-content/uploads/2012/11/IMG_3004-450x233-150x150.jpg 2012-11-29T22:27:57+03:00 Near the House Reservoirs The main problems associated with pond maintenance arise from water contamination. You can also keep fish in tap water, but given that chlorine is added to it, which forms acids with water, the water must be left for several days before introducing the fish so that the acid has time to decompose. During the summer heat, water should be added to the pond...Near the House [email protected] Administrator Near the HouseAlgae on the walls and bottom of the reservoir can become an assistant in keeping koi. But cloudy green water or “blooming” water is a common and undesirable phenomenon. If it is too intense and lasts longer than two weeks, it is time to take action.
The muddy, green water is inhabited by phytoplankton - single-celled algae and cyanobacteria capable of photosynthesis. The spores of these living organisms spread freely in the atmosphere and are necessarily found in natural bodies of water. If the water appears clear, the concentration of these microorganisms is low. In closed reservoirs, under certain conditions, these algae, of which there are thousands of species, can multiply very quickly. Some green algae move only with the current (chlorella) and are called planktonic, others are capable of independent movement (euglena, chlamydomonas). In total, there are 13-20 thousand species of green algae.
Their preferences for environmental parameters are so diverse that if a reservoir is unsuitable for them, then the fish most likely will not be able to live in it. Not only green algae cause blooms: diatoms color the water yellowish-brown, red algae turn the water red. Since predominantly blue-green microorganisms develop in fresh water bodies of the Northern Hemisphere, the water is colored in corresponding shades. “Blooming” of water occurs in the seas and even oceans.
Algae, the development of which is controlled by humans, can be beneficial for carp. This is additional nutrition, including in cold winter, when feeding has already stopped. The rest of the time, algae, together with specially planted plants, absorb dissolved organic matter and improve water quality. Some hobbyists believe that green water is beneficial for the color of fish - it is rich in zooplankton, the natural food of carp. Goldfish are successfully grown in such water in China, and even specially created in aquariums. But still, going up to your favorite body of water and looking at a motionless green puddle is a small pleasure.
The pond is filled with green, muddy water, through which not only the bottom, but also the shores are not visible. Fish are only visible near the surface. But the decorative aspect is not the main thing - there are also dangers of this phenomenon that are not so noticeable.
During the day, under the sun's rays, algae produce oxygen, and at night they absorb it. If their development is too intense, and the pond is overpopulated with fish, the fish may die early in the morning. In the middle of summer, when there is already little oxygen in warm water, the danger of this phenomenon is especially high. During the day, on the contrary, algae can produce too much oxygen and lead to oversaturation of the water with this gas. Small oxygen bubbles damage the gills and cause gas bubble disease.
Excessive algae populations affect the acidity of the water - pH. At night they release carbon dioxide and increase acidity. These sudden changes in acidity create discomfort for fish, which need a constant pH and do not want its sudden changes.
Excessive development of algae in a decorative pond becomes an undesirable factor affecting the quality of water and its inhabitants.
In short: because the conditions are right for them. No special actions are required for algae to appear in the water. This can be easily checked by placing a transparent jar of even drinking water in the bright sun - gradually a green or brown coating will appear on the glass. Adding flower fertilizers will make the water cloudy and green in color. In closed reservoirs, ideal conditions under which water “blooms” usually develop without human intervention.
Nutrition. Although algae can be content with little, the more food they have, the more actively they develop. Potatoes don’t need to be fertilized, but with fertilizing they will grow larger. There are many predators near large herds of herbivores. Not all of the algae’s nutrition comes from fish waste—the water entering the pond already contains the necessary substances. In the spring, koi begin to feed heavily after winter, and this simply adds new substances to the water. “Blooming” water occurs in the sea, where no one feeds the fish.
Light. Temperature. Photosynthesis requires light. When sunlight becomes more intense and prolonged in the spring, algae develop more actively. Algae activity depends on water temperature. The warmer the water, the faster they develop.
Killing all algae with pond chemicals or draining and cleaning the pond, if the causes of the phenomenon are not eliminated, will only solve the problem temporarily. When dealing with green water, you need to take into account as many reasons as possible and use several tools at once.
Biological control. Floating plants such as nymphs and water lilies shade the water. Cover one-third to one-half of the water surface with floating plants. Algae are much more resilient than higher plants, and they cannot be defeated by adding plants alone. Fast-growing species such as elodea, hornwort, and water hyacinth absorb organic matter and certainly will not cause algae to grow faster. The same function is performed by willow cuttings immersed in water. When adding new fast-growing species to control algae, keep in mind that such plants can also become a problem. To avoid getting a new nuisance, first think about how to limit their spread, and then add them to the pond. Lowering the water temperature will reduce algae activity. This can be done using a well, but in the summer heat the water will still heat up soon. In this case, you need to create a running water supply, but carp is a heat-loving fish.
Pond maintenance. Use quality feed. All food is not completely digestible by fish, but cheap food is also poorly digestible by fish and decomposes in water. To plant plants, use only soilless soils that do not release organic matter into the water. If there is garden soil in the containers, remove them for a while or replace the soil with any sinking soilless substrate (pebbles, sand, etc.). This substrate needs to be fertilized, but wait with it. Clean the mechanical filter regularly and remove organic debris from the bottom of the pond. Do not allow waste water to enter the pond (even if there are no algae problems). If there are no floating plants, the pond can be shaded with a net. Flowering plants need at least 6 hours of sunlight to develop buds.
Equipment and chemicals for pond water purification
A home pond cannot function independently, as happens in the natural environment. Sometimes “natural” ways to combat algae are not enough and you need to use special devices and water additives. After all, algae are living organisms that die under certain conditions.
An ultraviolet sterilizer is a tube-shaped device that destroys all microorganisms in the water flowing through it. It is usually placed between the filter and the pump, including when it is necessary to get rid of dangerous or unwanted population of the reservoir. Thus, the colony of bacteria we need for processing fish waste products is preserved on the surface of the filter, and the remaining microorganisms die. A sterilizer correctly selected for the volume of the reservoir will destroy unicellular algae and restore water transparency. A simple and safe solution to the green water problem. The sterilizer will not collect dust after getting rid of algae - it is used during quarantine and treatment of fish.
Chemical additives. There are many ready-made preparations for combating algae, including single-celled algae. Some additives cause the death of microorganisms, while others bind them together so that single-celled algae can be removed mechanically. There are additives that color the water and block sunlight, precipitating the phosphates necessary to feed algae. Be careful with any additions to your fish pond. Follow dosages and safety precautions! When mass destruction of algae occurs, timely removal of organic matter is important to avoid an ammonia outbreak. By the way, there are pond remedies for this too.
Briefly about actions against green water
If there is an outbreak of green algae in a pond, you can do the following.
Watch and wait. By reducing feeding, increasing aeration and trying to remove as much organic matter as possible. It is better not to do massive water changes, so as not to bring additional nutrition. Often the problem disappears within 2 weeks.
If there is intense and prolonged flowering, look for the cause. Usually this is overfeeding, overcrowding, poor food, waste water with fertilizers.
Plant floating and fast-growing plants, create shade.
Use an ultraviolet sterilizer and chemicals that are safe for fish and higher plants.
Remember that a pond is for fish, not algae.
Inna from Tyumen asks: “I built a small decorative pond on my garden plot and ran into the following problem: every year the water in it turns green, it becomes cloudy and all the beauty disappears. What can be done to prevent the water in the pond from blooming?
We answer
Finding a solution in the natural environment
A pond on a personal plot is created in order to perform a largely aesthetic function. After water has been poured into a specially prepared hole, it is time to take care of planting ornamental plants and populating the home pond with fish.
Almost all gardeners sooner or later face such a problem as blooming water.
Let's try to figure out why this happens by paying attention to the state of natural bodies of water in the context of the external conditions in which they are located:
- The cleanest and most transparent water is found in ponds with underwater currents, springs and streams.
- Active development processes of algae and bacteria are observed in those ponds that are located away from trees and shrubs, that is, in open areas.
The first option considered can be explained by the fact that the reproduction of blue-green algae (and we are talking about them if the water in the pond turns green) is very difficult in those reservoirs where there is running water.
The second case allows us to conclude that the use of emergent ornamental plants can bring not only a tangible visual effect, but also visible benefits. By taking food from algae, the latter help solve two problems in one fell swoop.
As for the connection between the location of the reservoir far from large plantings and in open areas and the proliferation of algae, its reasons have also been established for a long time: large amounts of sunlight contribute to an increase in algal blooms and their reproduction.
How to care for your pond at the dacha (video)
Options for solving the problem
Summarizing the properties that blue-green algae have, we can conclude: the fight against them can be quite successful, the main thing is to find the method that will be most acceptable for you.
So, what should you do if your pond suddenly blooms:
- Introduce emergent plants, such as water lilies. According to experienced gardeners, water hyacinth can also help. You can learn more about popular aquatic plants for ponds.
- Create conditions such that the reservoir is located mostly in a shaded area. If it is impossible to wait for shrubs and trees to grow, or you do not want to plant them, you can use artificial options, for example, covering the water with a dark film and keeping it on the water until the annoying greenery on the surface disappears.
- A solution with running water, at first glance, is not available for an artificial pond. But, if you look at it, nothing can stop you from arranging a small fountain in your pond.
Reviews and comments
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Dmitrich, Volgodonsk 28.04.2017
It all depends on the area of the pond and the volume of water. I have an area of 90 m2, a volume of 180 m3, three fountains, 45 calamus bushes, 30 hyacinth, 25 water lilies, 0 water lilies and 25 nymphs (lilies) The water is filtered before passing through the fountains, there are 100 pieces comets 25 koi carp and 20 red crucian carp, WATER YOU CAN DRINK
There was a time when springs of crystal clear moisture even protected from the violence of nature. Now, being in direct contact with precipitation and melt water, forming ponds, they begin to bloom. The phenomenon is, of course, unhealthy and visually unsightly.
As expected, it undergoes mandatory certification. Subsequently, the extracted well water is packaged in containers and supplied for sale as a food product. But there is evidence that the source can take on a bright green hue. It is not uncommon for algae to appear inside an open or uncleanly washed container.
Algae are, first of all, factors of improper storage and transportation. For example, prolonged exposure to direct sunlight and elevated storage temperatures are not recommended.
Greening may be caused by:
. the liquid was not borrowed from the well;
. contamination of the internal space of the technological water storage tank;
. contamination of bottles and small containers due to the fault of the consumer.
However, there is a cohort of specialists who claim the benefits of green algae. They say that there are no specific studies indicating that they are harmful to the human body.
Unfortunately, clean, ready-to-drink well water does not pass tests for the presence of organic matter, toxic chemicals, radionuclides and other chemically harmful contamination. These parameters are not tested and their concentration is not measured. Underground water intake structures are the main suppliers of drinking water. At the same time, laboratory quality control is increasingly putting forward the hypothesis that flowering and, specifically, greening of water is caused by storage conditions and a low level of cleanliness of the container. Modern quality control devices record the presence of suspended components exceeding the permissible norm. And the green tint clearly characterizes the presence of plants in the drink.
Methods for removing green water from a pool
To determine the routes of their penetration into the container, blooming water must be subjected to laboratory tests to obtain the appropriate conclusion.
For example, to remove greening in a swimming pool, you again need to know the indicators and reasons for their occurrence. For this purpose the following is measured:
1. Free chlorine indicator, water hardness, alkalinity level, mineralization and sulfate content.
2. Probable cause of green, cloudy fluid.
If this is detected or a slippery surface of the pool walls appears, rechlorination should be done to a level of 25 mg/l with free chlorine.
Carry out high-quality mechanical treatment of the entire area of the pool. It is advisable to maintain the chlorine content at a level of 3 mg/l. And to prevent the appearance of greenery, it is recommended to use the drug “algicyl” in the future.
Thus, only a competent choice of solution to the problem can lead to the elimination, in particular from the pool, of green turbidity.