Large Ponds

Pond Aeration Tips

It may come as a surprise to learn that fish need oxygen too. Without it they, just like you and I, would die. Pond aeration, or in other words, using an aerator, is one of the best things you can do for a pond and for fish.

A pond aeration system is normally an after-thought for people who own ponds. Maybe this is because we assume that water doesn’t hold much oxygen or that fish don’t need it, but nothing could be further from the truth.

Keep in mind that what we’re talking about here is not quite the same oxygen that you and I breath out of the air. Water actually holds dissolved oxygen (DO) and it’s vital to a pond’s inhabitants and to the pond itself.

Fish Health And Dissolved Oxygen

Regardless of the species for those with fish ponds, our friends with fins are often important whether it be from the high cost of some koi, to the sentimental value of a gold fish. There’s a good bet that large pond owners have a vested stake in keeping their catfish or bass in good shape too, so every pond, no matter the size can be affected by poor oxygen concentrations.

Fish actually breath through their mouth and as water is sucked in, it’s forced to pass through the gills where oxygen is then extracted from the water. Fish actually have nostrils as well but those are only used for smelling scents, not for breathing. Fish are very capable at oxygen extraction. Water tends to hold much less oxygen (about 2 to 5% of the air we breath on land) so it’s important to be very efficient and fish pull about 85% of the available oxygen out of water.

What Creates Low Oxygen In A Pond?

Even with this capability, fish will still have problems if there is not enough oxygen available in the water. Several factors affect the oxygen holding capacity of water. For instance as the water temperature increases, and particularly as it goes above 78* F. the capacity for water to hold DO drops pretty fast. This is why very hot, prolonged summer periods can cause fish losses.

Other factors that create a DO deficit include other substances such as minerals, chemicals or other gases, may take up space that would normally be available. If plants of any kind are present in the pond, they add oxygen during the daylight hours and pull oxygen at night and periods near dawn are usually connected with the lowest levels of the day. And if they experience a die off they will pull oxygen rapidly from the water if the plants are abundant.

DO is measured in milligrams per liter and most fish will do quite well at any reading from 5mg/L and above. If the dissolved oxygen concentration get’s below this amount, fish begin to become stressed and some may die. Larger fish are particularly at risk because they require more DO to function and survive compared to smaller fish.

Why Pond Aeration Helps

Oxygen get’s into the water in several ways. First when there is agitation at the surface, either through wind, or some other “disturbance” it’s much like a barrier is being broken and an active exchange of oxygen goes into the water and other gases may go out. As mentioned plants that are going through photosynthesis also release oxygen into the water.

However plants provide a give and take when it comes to DO and there are times when the wind either doesn’t blow or the temperature get’s so hot that the water can’t hold much DO anyway. It should also be noted that unless the wind is blowing really hard, the deeper parts of a pond may still have lower DO content compared to the water at the surface.

Fish can certainly adjust their depth to find the best oxygen levels and they may even resort to gasping at the surface in very stressed conditions. Apart from this the pond’s health may suffer due to low DO levels down deep. Much of the cleaning bacteria that help to keep organics and rotting material from building up at the bottom are aerobic and this means they too require good oxygen levels to work well.

The real answer to guarding against low DO in the hot summer as well as maintaining good oxygen counts in deep water is submerged aeration. A typical aeration kit will have a land based pump (either electrical. solar, or windmill generated), an airline, and a diffuser system that sits at the bottom of the pond. This system drives air out the diffuser in a very fine bubble array that rapidly rises to the surface of the pond. This movement not only helps create a “break” at the surface to help with oxygen exchange there but it also creates a type of vortex of water movement that goes up to the surface, across the top of the pond, then back down to the bottom again. This allows a better, more widespread distribution of oxygen loaded water throughout the pond.

Many pond aeration trials have shown that fish loss can be either lessened greatly or eliminated entirely with adequate aeration.

Pond aeration systems are all similar in how they work. Most kits are rated in terms of the pond size and depth they they will work best at and to get the best results it’s suggested to consult the manufacturers recommendations on a particular system.

Costs will vary but most small pond systems are quite affordable and range from about $50 up to $500 while large pond systems can range from $600 or $700 up to several thousand dollars. Operational costs are relative to the size of the system but are generally affordable for most pond owners.

All Season Aeration

It may seem that the warm summer months are the best time to use aeration and while that’s true, there are also benefits of using pond aeration in the winter as well. In moderate climates an aerator alone may help keep the pond’s surface free of ice and at the very least it’s a good idea to keep a section of ice open even in the coldest conditions. Large waters benefit here too and the most effective tool for this work will be an aerator package.

Consideration should be given to the placement of the diffuser sitting at the bottom of the pond. In the summer it’s suggested to put the diffuser in the deepest part of the pond to allow full oxygenation and circulation. In winter, the diffuser should be moved to shallow water, not only for it to keep a hole open in the ice but also to allow the fish to go to deeper water and be undisturbed. Normally in winter, deeper water is warmer.

It’s unfortunate that many fish pond owners don’t make the move to add aeration to their pond until or after they’ve experienced some fish losses. It’s a hard way to learn a lesson but the promise of a healthier pond and fish can be the result after adding a good pond aeration system.

Pond Algae Control Tips

by Mark

Pond algae control honestly isn’t something that most pond owners think of when they’re first starting out. Usually we have visions of a beautiful fish pond full of koi or goldfish, some pristine plants, and a breath taking waterfall. The last thing we think of is everything turning green!

The sad reality though is that for many, the fight against pond algae, and learning how to control it is something most people will have to deal with.

Pond algae can show up in many forms but the most common will be some type of string algae, which is thick strands of growth that may extend up from the pond of the pond or spread across the surface. It would be hard to compare string algae to anything other than maybe spinach which might be good for you, but many people don’t like that either!

Another very common form of algae is green water, which is actually made of up single cell algae of various species. The color of pond water can vary from a light tinting of green or brown to a heavy, seemingly solid soup of green color. One would think that nothing could survive in water like this but the fact is, in most cases, fish will do fine. A pond owner won’t however because they may go months without ever seeing their prized koi.

Algae can be found clinging to the sides of a pond, whether it’s natural or has a rubber liner. Waterfall rocks are also a prime growing ground even though they may have a constant flow of water running over them.

What Causes Pond Algae?

It’s important to realize that algae is like any plant. It needs certain things to grow well, and if those things are present…well you know the rest of the story.

What we’re talking about here are things like ample sunlight, abundant “fertilizer” or plant food, and relatively warm temperatures. Sunlight and temperature are pretty self-explanatory, but what about the food for algae?

If algae were a vegetable most gardeners would get this one right away and particularly when we start talking about compost. Compost is, for the most part, made up of dead organic material that is slowly rotting away or being naturally broken down into other forms of stuff that can be used, consumed or assimilated by something else. Your pond actually has some compost in it too.

It might be dead leaves, grass clippings, dying pond plants, dead algae and other good things like that. Coupled with the waste from fish, you have an organic cocktail that algae will surely love. And it doesn’t matter if your pond is big or small, the same general principals apply (although fish have much less affect in larger waters).

A Common Algae Treatment

Common sense would usually suggest that the best way to handle an unwanted growth of algae is to treat it like a lawn weed. With those most folks would either pull it out manually or try to kill it in some way, and so it is with algae.

Manual removal is really a safe approach to dealing with string algae (it won’t work on green water obviously) but it can also become quite a chore if the algae is growing quickly. After awhile the ongoing frustration may lead to simply wanting to kill the plant with a chemical known as an algaecide. These usually contain some form of copper or copper sulphate which is toxic to most algea.

There may be times when an algaecide is useful and effective but there are also trade-offs in using them. First of all, as we noted above, it’s organic nutrient levels that greatly determine whether algae will thrive or not and as long as they’re present, algae has the opportunity to grow aggressively. This means that if you take the chemical route, you’ll need to use them often to keep things in check. Normally when an algaecide is applied, algae will die off very fast, and this can pose a hazard to fish. When any plant dies, it will pull dissolved oxygen from the water and the fish need this to survive. And some areas around the U.S. are now banning the use of copper algaecides because of an increase in the metal concentrations in their water systems.

Despite the fact that algaecides may not address the root of the problem of algae, they may have some benefit to controlling spots or areas of growth that may be stubborn. Nature however has a better approach in many cases and that’s by using special bacteria to help break down organic elements in the pond and lower nutrients. This is, in a sense, Mother Nature’s pond cleaning mechanism and it works well if it’s supported and natural algae control is possible.

Most of the bacteria that’s doing the work is aerobic which means in needs oxygen to function. Some ponds have good levels and some don’t, and for those that do not, an aeration kit may be very useful. Coupled with some supplemental beneficial bacteria, many ponds can be restored and algae reduced without the use of chemicals entirely.

Small fish ponds benefit greatly from this approach because it’s much safer than using a chemical algae killer. Owners of large ponds can also lose fish because of misapplication of a chemical too, so no one is immune to risk, and therefore, biological tools can be useful on big water as well.

Other Algae Control Tools

In addition to algaecides, beneficial bacteria, and aeration, there are other tools that may help with algae issues. One worth investigation, and particularly if your pond is large, is ultrasound or ultrasonic algae control. This device uses sound waves, specifically tuned to match the vibrational frequency of an algae cell. As this sound wave travels through the water is creates a resonance or vibration in the algae and it begins to break apart.

Ultrasound seems like science fiction but it does actually work and has proven to be effective a good deal of the time. Many industries such as waste water operations are beginning to use it more for controlling algae in lagoons and basins. And pond owners can benefit as well.

Pond dye is another tool that may help with algae problems. Since sunlight is a major support of plant growth, limiting this exposure may reduce algae of various types. It works particularly well on algae at the bottom of a shallow pond.

And finally, many people have heard about, and asked about barley straw. Dried barley straw has been used overseas for many years to good effect and both small and large ponds have benefited somewhat from using it in the U.S. As the straw decomposes in the water it releases several substances which have proven toxic to some types of algae.

Barley straw may not work in every case but when it does it can provide several months of good control and a relatively low cost. The only way to really know if it will be effective in your particular pond is to try it.

Using A Lake Rake For Pond Weeds And Algae

by Mark

Some large pond owners find themselves in a battle as pond weeds and algae attempt to take over their ponds. In spring and summer around most of the U.S. it’s not uncommon to see algae growing well on many waters and pond weeds growing below the surface.

For some time now, the most likely response to dealing with the problem has been to apply either an algaecide, designed to kill algae, or a herbicide which is often better for weed control. These chemicals can contain any number of things but copper is a common ingredient and because of this there is a growing trend to try and move away from such applications.

Environmental awareness is building each year, and with it, pond owners are looking at other options besides chemicals.

One particular tool that’s become popular is the lake rake.

Lake or pond rakes come in different shapes and sizes and most have long handles or rope tie lines that allow for easy retreival of the rake. The teeth on the rakes are normally longer than a standard garden rake and in some cases they may project off both the top and bottom of the rake head. Float attachments are available as well to make them more effective on floating algae or pond scum. By removing the float the bottom can be dragged to remove loose plant and algae material.

They’re very simple to use. Just toss the lake rake into the pond targeting amongst the algae growth and then pull the rake and the accumulated weeds back in to the shoreline. The removed plants can then be put in a wheel barrow or other transport to move them away from the pond.

A lake rake should not be confused with a pond weed cutter which is also another tool that’s growing in popularity.

As the name implies, cutters are intended to remove rooted weed growth at the bottom of a pond . They’re similar in that you throw the device out into the water but then allow it to sink and begin pulling it back in. As it’s drug near the bottom of the pond it will cut through and sever any plants quite low on the stem. Along with the manual versions, there are powered, boat attached models as well. Once the pond weeds have been trimmed, a pond rake can then be used to remove the cuttings. So the two tools work very well together and are often marketed in this way.

Most manual lake weed rakes are fairly affordable with prices ranging from about $70 up to $130. Powered models such as a lake mower will cost up to several thousand dollars in some cases. So there’s a great savings with the manuall models although you have to provide the elbow grease to get them to work.

For those that are looking for a non-chemical option to algae and pond weed control a lake rake may be one of the better options. They have their limits, such as working best around the shoreline and in shallower water, but in many ponds this tends to be a trouble spot anyway so they may fit your needs quite nicely.

Pond Dye For Algae And Weed Control

by Mark

Pond algae and aquatic weeds are a common problem for many people. A common question that’s often asked is, can pond dye help?

In most cases, the answer is yes. To stop algae and weeds from taking over, pond dye can help get the water cleared up once again. There are many dye products available to address such situations. They work in a natural way, which will not harm fish, frogs and other aquatic life that may exist under the water’s surface. Such products are safe for humans, pets and other animals. If used correctly they will not discolor skin or hair.

Blue pond dye does not work by directly killing the unwanted algae and growth. It works by blocking light that is essential for the growth of plant life. Though much of this growth may sit on the bottom or bed of the lake, the sun’s rays are still able to get through to continue the process of photosynthesis. Aquashade, which is one type of dye, works by diffusing the sun’s rays from getting past the surface of the water, and limits light exposure to the algae and other unwanted plant life that grows from the lower regions of the water.

Using a natural product has many obvious benefits. There is no need to worry about pets or children being harmed by playing in the water. Fish and other live creatures do not need to be removed prior to treatment. Chemicals, such as algaecides or herbicides, can leach into the ground surrounding the water source. If gardens or other planting areas are located nearby, they could be affected. Pond dye does not add harsh chemicals and is non-toxic. It is good for the water source, the surrounding area and for those who play in or near the water.

If you decide to use a product such as pond dye, do not be alarmed when it comes out of the packets or container looking black. It will get lighter as it disperses throughout the water. It is important to use enough product to treat the entire lake effectively. The natural movement of the water should disperse the entire contents throughout the entire surface within a day or two.

A typical pond dye product will cover a one acre water source up to five feet deep. Therefore, it the water is deeper, an additional gallon may be required. During this time, it is advisable to keep out of the water, until the crystal blue color has spread throughout the entire area.

It’s advised to wear rubber gloves, so the tinting will not get on hands and stain them. This is particularly related to the liquid dye, as the powdered dyes that come in water soluble bags is a bit less messy. Pond dye products for large ponds range in price from $30 to $79 and can be purchased in quarts or gallons. In terms of some concentrated dye, a single quart can treat up to one acre in size. There is no limit to the number of times pond dye can be used in a year.

For the best results, it’s suggested to use the first application at the beginning of the growing season, to catch algae or weeds before they get out of hand. Early management and control is often easier rather than waiting until the problem growth get’s well underway.

Pond Dredging Equipment And Cleaning

by Mark

Is pond dredging the best way to clean and restore your pond?

It’s a simple and natural fact. Large ponds and lakes will fill in over time and in time, that grand old pond that once stayed clean and clear, now has algae or other problems. This process is known as eutrophication. One of the main causes of pond algae blooms is the build up of organic material, muck, and sludge at the bottom. Things like leaves and other stuff fall or get blown into the water and sink and erosion might also play a part.

Being made up of organic elements, most of this sediment is a lot like compost in a garden. We all know that you can get any plant to grow better with good nutrients and anything organic that’s breaking down, in soil or water, will improve the vitality of a plant. Good for vegetables, bad for algae unless you’re using it for bio-fuels.

This fact makes it pretty obvious why a pond owner would want to clean up the bottom of their water-filled basin.

There’s really two ways to do it. The first process would be to use beneficial bacteria, or microbes and enzymes, to help break this sludge down and in effect, eat it away. This is nature’s method of cleaning and it works very well, and quite safely, but it does take a fair amount of time. On average with proper aeration running to help these aerobic bugs do their work, one could reasonably expect 3 to 6 inches, and possibly more muck reduction in a six to eight month season.

The second option, and one that is much quicker although usually more expensive, is to dredge out the pond bottom. Dredging equipment can help make pond restoration a relatively quick task where a great deal of build up can be removed in one to several days of work.

Planning and using the best tools for the job is important, and it could be said that there is not a single solution for every pond. Let’s look at the most common approaches to pond dredging.

Mechanical Dredging Equipment

The mechanical approach to dredging will involve some form of equipment such as a clamshell bucket and crane, a dragline, which uses a bucket with holes in it which is dragged across the bottom, or excavator dredging that uses something like a backhoe device. Because fairly heavy equipment is used in all of these operations, rainy weather can affect work times.

Hydraulic Dredging Pumps

A hydraulic dredge will actually float on the surface of the water and uses a pipe to suck stuff off the pond bottom. It’s similar to a very big muck vac that will remove sediment with great precision. The waste material is routed far away from the pond and released through a discharge pipe.

Of the methods of hydraulic dredging used, the most common are the auger dredge, or some type of cutterhead dredge. These tend to be very efficient in terms of how much sediment they remove and how much manpower is needed to do the work.

Once the muck is removed all the wet sediment should be dewatered or dried out to allow for easier removal from the pond site or it can be used in the area for structuring the landscape surrounding the pond.

So What’s The Benefits And Risks?

The benefits of dredging a pond, as noted above, include a very rapid and efficient reduction of sedimentation build up which can lead to many water quality problems. It’s a very direct way to increase the depth of a pond and a necessary step in most large pond restorations.

Dredging is not without it’s risks however. In many cases the water in the pond will need to be drawndown, or lowered to allow easier access to the bottom. As digging begins there is a good chance that bottom sediment may be disturbed enough to affect the ecology of the pond. Fish breeding and feeding habitat can be altered enough to affect populations negatively. And finally, additional nutrient rich sludge can be released and circulated, which can rapidly lower oxygen levels in the water. To guard against this it’s advised to use a quality aeration system in the pond during excavation as well as after the restoration is complete.

All in all, pond dredging may be the best solution for restoration of a natural setting. It’s not without it’s risks or costs, but it has proven to be the most efficient way to return a pond to a more youthful condition.

Pond Aerator Or Fountain – What’s Best?

by Mark

When you drive by some great looking large ponds, and particularly those on golf courses or commercial properties, it’s not unusual to see the beautiful spray of water from a floating fountain cascading through the air. There’s no question pond fountains are popular and provide a great display.

Contrast this to the more covert pond aerator that sends air to the bottom of the pond. In man cases the most you’ll see is some ripples and light bubbling at the surface of the water. They seem so subtle in there work, most people won’t even notice that they’re there.

The question often comes up wondering which one of these systems is best. To appropriately answer this question, it’s best to compare to the two and also discuss the types of ponds that they work best in. There’s no question that each system is unique and different, and depending on the circumstances, one is really better than the other in our opinion. [Read more…] about Pond Aerator Or Fountain – What’s Best?