Everyone is looking for ways to accomplish jobs once handled by chemicals or physical labor in a more environmentally favorable, and less labor intensive way. One such treatment for filamentous algae (also known as pond scum, blanket weed, pond slime and other names) problems is the use of barley straw. Barley straw has been shown to prevent "blanket weed" or filamentous algae when used properly in ponds. It is thought that the decaying barley straw produces an enzyme that prohibits algae growth, but most experts will tell you that they honestly don't know exactly why.
All of the parts of your pond or lake interact with all of the other parts. Each problem you have is a part of other problems, probably leading back to a single problem at some point. pH, lake fertility, dissolved oxygen levels, fish size and weight, and lake vegetation each have something to do with the other, therefore, it is important to trace any problem back through each factor, and find the primary cause. As an example, we have a 4 part series about how these interactions occur. Pond Scum Lake Weeds Mosquitoes And Skinny Fish Controlling pond scum, lake weeds and mosquitoes and raising healthy fish may seem complex and difficult. There is no miracle cure, there is no magic bullet. Pond Scum And Lake Weeds Most of the questions we receive about lake weeds revolve around how to get rid of them. As with pond scum, most lake weeds get their start at the bottom of the pond when sunlight reaches them. When conditions are right, they may grow out of control causing problems for the pond owner. Mosquitoes And Skinny Fish Mosquitoes on ponds and lakes may seem to be unrelated to lake weeds and filamentous algae. The truth however, is that mosquitoes become a problem when there is too much vegetation in the pond... If the water has too little of one type of algae, and too much of another, the ponds life cycle is interrupted, and the fish go hungry, resulting in skinny fish. Pond Scum And Lake Weeds The Real Problem The problem is sunlight. You can’t do much about that. Specifically, the problem is sunlight reaching the pond bottom, which you can do something about!
Part 4 in our series on lake and pond interactions
The real pond scum and lake weed problem
The problem is sunlight. You can’t do much about that. Specifically, the problem is sunlight reaching the pond bottom, which you can do something about! The common issue for pond scum and lake weeds is sunlight penetrating the water to the bottom of the pond or lake. When this happens, a process begins which will allow lake weeds to grow unchecked, pond scum to develop and start to rise to the top, and the secondary result will be mosquitoes, and even though the plants and algae will produce oxygen, they will at some point cause conditions which will deplete oxygen in the water, and all the while, your fish will be starving. All of this because sunlight reaches the pond bottom!
Preventing lake weeds and pond scum by preventing light penetrationThere are a number of ways to prevent light from reaching a pond or lake bottom. You can raise the water level, lower the bottom through dredging, or color the water in some way. Raising the water level can produce good results in some cases, but may not be practical, and it still doesn’t deal with the issue of skinny fish. If the water is deep enough the sunlight cannot penetrate, but something needs to be done to feed the fish if the water is clear to a depth of more than 24 inches, so even if you can raise the water level, or dredge the shallow areas, more is needed. The water needs color to shade the bottom. This can be done with dyes and colorants, but, once again, you still have the issue of skinny fish. There is a product that can resolve both the light penetration issue, and the food supply issue.
PlanktonPlankton is a single cell algae which is suspended in the water of healthy ponds and lakes. It provides oxygen to the water, food for the tiny invertebrates that feed the larger aquatic life, which ultimately feeds the fish in the lake, and provides color for the water helping to prevent the excessive growth of unwanted vegetation and pond scum. This is sometimes called algae bloom.
Producing algae bloomThe reason that plankton does not grow in a pond or lake is lack of fertility. The solution to this problem is to add fertilizer. To learn more about this process see: pond scum prevention and Lake weed prevention Pond scum is filamentous algae, and is also known as blanket weed, pond blanket weed, and a few, less desirable terms.
Part 2 in our series on lake and pond interaction
Pond scum control
Most of the questions regarding pond scum, lake moss, or pond algae ask how to get rid of it. This is perfectly logical. The problem is, that the pond scum itself is just a symptom of other problems. The first evidence we have of it’s existence is when it floats to the top and interferes with the aesthetics, our recreation or our fishing. Filamentous algae, or pond scum as it is more commonly known exists in most bodies of water, and will begin to show itself when conditions are right for it. It grows from the bottom, and sunlight allows photosynthesis when it penetrates to the bottom. The photosynthesis process allows the algae to take in carbon dioxide, and exhale oxygen, some of the oxygen, which is good for fish, will be released under the algae mat, and gradually cause it to float to the top, where it becomes a nuisance.
Lake weed controlMost of the questions we receive about lake weeds revolve around how to get rid of them. As with pond scum, most lake weeds get their start at the bottom of the pond when sunlight reaches them. When conditions are right, they may grow out of control causing problems for the pond owner. Some aquatic weeds are capable of doubling in mass in a week or less, leaving the pond owner with a huge aquatic weed control problem. If measures are taken to kill the weeds with aquatic herbicides, the weeds will die, and drop to the bottom where they will decay over time. This can produce a slimy, and high organic fertility on the pond bottom, perfect to supply nutrients to the next generation of weeds!
Mechanical lake weed controlMechanical controls and mechanical lake weed harvesting may produce less slime at the bottom, but care must be taken when using a lake weed cutter to collect all the fragments, as aquatic weeds are notorious for their ability to reproduce from fragments. One plant chopped into 100 pieces may turn into 50 new plants in a matter of days. See: The relationship between excessive aquatic vegetation, Mosquitoes And Skinny Fish
Pond Scum Prevention Pond Algae
We are all aware that pond scum may be the secret of the fuel production of the future, but in the mean time, it is probably not something you want in your recreational fishing pond. For one thing, it is ugly, for another, it is often stinky, and to make matters worse, it can do harm to other forms of aquatic life, and harbor potential disease carriers like mosquitoes. Not all algae is bad, but an abundance of blanket weed pond scum, almost always has an adverse effect on aquatic life. You can find the proper distinction between the filamentous pond algae that plagues pond owners, and the types of algae necessary to maintain healthy pond life below.
What causes pond algae?Algae is always present, but what causes it to spring up in such dramatic fashion in the spring and summer? The best answer is sunlight. Pond algae starts in the bottom of a body of water, in spite of how it may appear. The floating mass you see at the top of the pond is algae that started on the bottom, and gained buoyancy as it took on air, and floated to the top in the stinky familiar mass. Sunlight penetrating to the bottom of a pond starts the photosynthesis process, and kick starts the whole nasty mess.
Different types of pond algaeSo, is all algae bad? The answer is a resounding NO! In fact, the best means of preventing pond scum, or filamentous algae, is by producing another type of algae. Plankton. This single cell algae will remain suspended in water, providing food for the tiny animals that provide food for the larger life forms, which in turn, provide food for your fish, and, if you are a successful angler, food for you.
Pond algae control using algaeNot only does this type of algae feed the fish, it also colors the water. That nice green or blue green tint that you see in healthy ponds and lakes is suspended algae, and one of the best services it provides is tinting the water, thereby preventing sunlight from reaching the bottom of the lake or pond, preventing the growth of unwanted vegetation, and providing pond algae control. Yes, pond scum, like most aquatic plant life, gets it's start at the bottom of the pond, and as it gains oxygen, it floats to the top where it produces all sorts of undesirable conditions, like the ones mentioned above, and including lousy fishing conditions, oxygen deprived fish, and frustration.
Algae for tinting the waterGetting rid of the pond scum type of pond algae can be a difficult task, and if the conditions that allowed it are not changed, it will return. Remember, the problem is sunlight reaching the bottom of the pond, so something must be done to prevent it from doing so. This could include raising the water level, which may not be possible in all cases, dredging or otherwise making the lake deeper, or coloring the water. The last, is usually the chosen option. There are dyes which can color the water, but, if fish production is what you desire, remember that dyes do not feed the fish. In small ponds for catfish production, where regular feedings occur, this may work, but where no feeding takes place, or where other types of fish are desired, dyes are not the answer. Once again, plankton is needed to continue the life chain, and prevent the pond scum problem.
How to produce plankton to prevent pond algaeSo, how do we produce this plankton? The answer is simple: Fertilize the pond. Now before you start thinking that it is a crazy idea, let me do a little explaining. Fertilizer, usually a fertilizer high in phosphorous, will encourage algae production through a process known as algae bloom, and this will produce the coloring needed to stop pond scum. There are a few things you need to check before you fertilize.
- First, get rid of the existing pond scum, and give it time to decompose.
- Second, test the water pH. Anything lower than 6.8, and you need lime to raise the pH. Something between 6.8, and 8.6 is ideal. If it needs correcting, correct it before proceeding.
- Third, check the secchi depth. It should be between 18 and 24 inches. If the secchi depth is less than 18 inches, there is another problem. If it is more than 24, begin fertilizing as soon as possible, and continue the process throughout the summer, or until the depth is less than 18 inches.
Other factorsThere are other factors, like muddy water, which will need to be solved before pond algae treatment, and you will need to know the details like how to use a secchi disk, and how much fertilizer, which are covered in other places on this website. See: How To Fertilize A Pond Or Lake Note: Filamentous algae goes by many common names: Pond algae, pond scum, pond slime, pond blanket weed, string algae, and others. There are other types of algae present in many ponds, some of them are beneficial to the ongoing health of the pond. Chief among these is the algae known as phytoplankton or simply plankton, the simple single cell algae that is suspended in water, and produces food for the life chain.
Filamentous algae, otherwise known as pond scum, is a nightmare for many pond and lake owners. The pond scum problem has a lot in common with other types of lake vegetation problems, and the cure for one will probably cure both. So, how do you get rid of pond scum? There are a number of different treatments, but the best method for dealing with pond scum is to prevent it from starting, and the method of prevention may come as a bit of a surprise.