Spring is an exciting time of year. The yawn of winter yields to longer days as the sun starts its annual earth warming. Flowers blossom, pond water warms and comes alive. Geese and ducks make theirs treks north and spring showers stimulate life in our ponds.
A pond waking from winter slumber is a wonderful experience. Fish move shallow and begin to spawn and feed. Plants begin to grow. As plants along the shore begin to bloom, so do the algae in the water column as well as the weeds in the muck.
Algae…that little prehistoric plant seems to strike fear, even in the most grizzled pond managers.
As pond managers, it’s important to harness nature to our advantage and understand water quality, rather than just the traditional methods of running around trying to kill algae and plant life. For a long time it’s been kill, kill, kill. Essentially, what that gets us is exceptionally hearty, hearty, hearty strains of algae and plant life that become immune to traditional chemical treatment protocols, not to mention fish you may not want to eat.
A better approach is about balance. In our laboratory we strive to discover what may balance each individual pond by studying all the forms of nitrogen and phosphorus, some iron, silica, manganese and alkalinity and taking a look, via microscope, at algae species. When you can identify water’s “ingredients” and then algae species of consequence, you stand a better chance to develop a custom protocol to deal with unwanted plants and enhance the ones we might prefer.
What works in one pond may not work in a pond 50 feet away simply because of differences in soils, plants and age. Some pond managers prefer to remove nutrients, while others often add minerals and nutrients into some ponds. Each has its own competitive ecosystem.
Green Algae versus Bacteria – Battle Royal at the Base of the Food Chain.
Generally, each spring, green algae take off. At the same time algae begin to thrive, so does bacteria…sometimes faster and sometime slower, but they are competing for many of the same nutrients. There are thousands of types of green algae. They are green because they use chlorophyll to harness the sun’s energy to produce sugars. In this process of photosynthesis, algae use nitrogen and phosphorous, muck, hardness, iron, and a plethora of other materials present influences what type of algae will grow. Each type of algae prefers slightly different conditions. One may prefer high nitrogen and low phosphorous while others may like high phosphorous and low nitrogen.
Algae’s competitor, bacteria, has two general types in pond water. The first type we call ‘heterotrophic’ bacteria. These pacman-like bacteria basically derive their energy from any organic substrate. They grow very fast and in the best spring time conditions their doubling times are 30-45 minutes. These microbes are tolerant of many herbicides, although copper slows them down quite a bit. Heterotrophic bacteria take up phosphorus and some nitrogen into their cell walls. Often, at the beginning of the spring, when the water is still cold, we’ll prescribe a cold-water bacteria that can jump start a pond’s biology to try to take up excess nutrients and compete before rooted plants begin to grow.
The other types of bacteria are called ‘autotrophic’ bacteria. They thrive on inorganic matter such as ammonia. In this case, we referring to a group of organisms call ‘nitrifiers’. Unlike heterotrophs, autotrophs are slow growing and chemicals kill them quite easily, and yet they are very important to the ecosystem under water. “Slow growing” means it may take autotrophs three days to double in population in the spring. Autotrophs are important in a pond loaded with geese, ducks or lots of koi or other fish that give off different forms of nitrogen as a waste byproduct.
The removal of ammonia by bacteria and oxygen is called ‘nitrification’ and the reaction look like this.
Nitrogen Waste à NH3 (ammonia) à NO2 (Nitrites) àNO3 (nitrates)
NO3àN2 (nitrogen gas)
The great thing about ammonia is when a pond is properly managed; you can get rid of it. It will break down and go off as gas and escape the environment. It’s also important to note that the best source of these autotroph bacteria organisms is from runoff from the soil. This is one reason why ponds look so nice after a gentle rain and so bad during a drought.
When certain chemicals are used and autotrophic bacteria are depleted in the water column, a pond grows susceptible to new problems. Good aeration favors the growth of bacteria and that is why aeration is so helpful and important, because it’s not just moving the water around and infusing oxygen, it’s really growing bacteria, as well.
While nitrogen can be diffused into the atmosphere where it belongs, phosphorous, on the other hand, just precipitates and collects on the bottom. There is no phosphorous gas that goes off to the atmosphere. Bacteria and some plant can take up phosphorous, only to release it later when they die, or it can be precipitated, but it will always be there unless physically removed. There are numerous ways to precipitate phosphorous and some of them bind the phosphorous very well, but it will always tend to stay behind.
It would be nice if there was one sure-fire way to manage a pond, but if there was, it wouldn’t be quite as fun. Each pond is its own dynamic entity and our job is to do what we can to interpret and adjust it to meet our goals. The first rule we live by is to understand water quality, what is going into a pond, and what kind of pond bottom you have. If you need to have some test run on water quality and also determine the types of algae you have present, send us your sample(s). We will give you the knowledge and determine a prescription of the best materials to use. The more you know, the better prepared you will be to manage your pond.
What can you do? It depends on the parameters. You might need to inoculate with certain species of bacteria. You may need to add nutrients to enhance the balance between different nutrients to promote the growth of healthy plankton. But, having a good starting point aids your decision-making process.
Last year we spoke with an acquaintance in Virginia, who is a chief scientist for NASA and one heck of an engineer. His pond was superbly engineered; it has a nice waterfall, excellent aeration and a clay liner. In an adjacent pond, his wife was raising a lot of ducks and swans, notorious producers of hot nitrogen waste. In the spring, he started up his pond’s waterfall and aeration system and it instantly turned as green as a cucumber while the adjacent pond looked nice. After several months he asked us what he should do. We asked him what his liner felt like and he said rubber. This was the wrong answer. You see, the liner of a pond should feel like slime…the slime that you would associate with a good biofilm. Biofilm is a sure sign of healthy bacteria doing their job. He was using bacteria, which was doing a nice job of eating up the duck waste, but that was easy to do with all his aeration. His issue was finding a way to use up the nitrogen that all these lovely ducks, swans, and koi were generating. It was being uploaded into the water faster than the pond could naturally excommunicate it from the water. We recommended Nitrafix which targets nitrogen in the water column and to get a sump pump started from the adjacent pond to bring some water over to the new pond. That water had what it takes to rapidly cleanse itself. In two weeks his new pond cleared right up and it has remained clean since. The liner now feels like slime because it’s balanced and the bacteria, algae and other life forms are in harmony. The biofilm on the liner is one example of this pond’s health.
Every pond can be figured out. After all, the harmony of a pond’s water helps lead to the harmony of the rest of the biology that spreads throughout the living, breathing happy place your fish and plants call home.