Closing Comments
In writing this guide, we hope we have given you all the basic information you need to make informed decisions on how to address your pond maintenance needs. A good maintenance program and a properly maintained pond will require less effort than a neglected or sporadically maintained pond.
Once you have the aeration system doing the primary job, you may want to add other circulation for additional water turn-over and visual appeal. There are a variety of options for water circulation including waterfalls, and fountains. Water movement is an important part of the look of your pond. Do you want an active pond that has large water displays? Do you like waterfalls and streams? Do you prefer a tranquil placid pond that just looks nice? What about the expense of installing, running and maintaining these systems? These are the questions you have to answer when you begin to assess your circulation needs.
It is important to remember that 'all water circulation is not the same' as far as benefit to you pond goes. Water will move in channels through the pond. This provides movement to some areas, leaving other areas without movement. Sediment deposits will be heaver in the dead areas. Water channels tend to remain near the surface, which will help keep the lake surface free of debris and scum. Heavy water movement can help prevent certain algae's from forming in the circulated areas. Debris tends to move toward the intake lines of you circulation system, so they should be located where debris can easily be removed. Skimmer baskets can be included to catch debris. This condensing of the surface debris, or collecting it in skimmers, can be a great time saver when you are skimming and cleaning the lake surface.
Too often, we see ponds or lakes that have become management nightmares, diminishing their aesthetic, as well as functional value. Many times, these problems could have been avoided. Knowledge of the dynamics that affect water quality make it possible for pond keepers to effect solutions which will make water features less problematic and easier to manage.
Nature has supplied us with an effective water clean-up tool, aerobic digestion. Aerobic bacteria will metabolize organic nutrients in the water, making them unavailable for vegetation. When a pond is in balance, there are sufficient levels of oxygen in the water to allow the bacteria to respire and digest these nutrients. When nutrient influx outstrips the bacteria's metabolic rate, the lake is thrown out of balance. The bacteria cannot keep pace with nutrient loading, and nutrient levels explode. We commonly see algae bloom as the result.
All water features have a life cycle; as they gradually fill in with sludge and nutrients and the aging process accelerates. By remembering the factors which impact water quality (nutrients, temperature, light, depth, and outside influences) you can make proper management decisions and chose tools to create lakes and ponds which are functional, beautiful and have a long life. Integrated lake management, or combining several practices, can help ensure your lakes never reach crisis levels.
Once you have good water movement and the waterfowl and runoff issues are addressed, you should decide which chemicals are needed to most effectively address the existing problems. Generally, one of the basic copper algaecides, coupled with a contact herbicide if you have weeds, is a good way to begin.
We usually prefer to address weeds and algae on a spot treatment basis. Treatments can be made to one area of the lake at a time and the risk of oxygen depletion or serious problems with water chemistry can be minimized. Copper based algaecides and herbicides can be effective on both weeds and algae, especially in the early season.
Once you have made initial chemical treatments to address the established problems in the pond, you can begin treatments of the microbes. Wait one week after chemical treatments before the fist bacteria application. Generally, we like to make treatments to the ponds on a weekly cycle. Since every pond is different it isn't possible to write a precise treatment schedule, and the experience of the pond-keeper is an important factor on making these decisions, these guidelines that might be helpful.
Bacteria can be applied successfully in water down to 50° F. Ponds are usually very nutrient-rich in the spring because there has been very little biological activity over the winter to use up these nutrients. When water temperatures reach the 60° F, weeds and algae will begin to come out of winter dormancy and begin to grow. You will want to apply algaecides or herbicides to begin to control the new growths before they advance very far. Once you have made initial chemical treatments, wait one week before making the next microbial treatment. These bacteria break down dead organic material so, it is important to let the chemical treatments do their work before making the follow-up microbial treatments. We recommend applying supplemental bacteria every two weeks throughout the growing season. Make any needed chemical treatments on the alternate weeks. This quickly becomes a standard treatment schedule. First make any spot treatments needed to control any current growths, follow this up one week later with microbes to breakdown the free organic nutrient and biomass, wait one week to decide if additional chemical treatments are needed. You should only use chemicals on actively growing aquatic plants and algae, dead algae will be consumed by the consistent bacteria treatments.
Remember, your goal is not the total removal of all vegetation from the pond, but to reach a stable equilibrium where the available nutrient is consumed by either the microbial population or the aquatic plants which produce oxygen and sustain the aerobic microbes. Your pond should have 15 to 20 percent coverage with light to moderately heavy aquatic plants. Moderate growths of filamentous algae or Chara can help keep the water clear while reducing planktonic algae, which is the least appealing variety of algae. This ecological balance is in constant flux; when you kill aquatic weeds, algae may grow, when you kill filamentous algae or Chara, planktonic algae may grow. When planktonic algae grow, it reduces sunlight for aquatic weeds, the weeds die, releasing heavy nutrient into the system. Without the weeds, oxygen can drop causing fish kills, and changes in the microbial population. Aeration and well timed chemical treatments can overcome these ecosystem crashes, giving the aerobic bacteria a chance to reduce nutrient levels and stabilize the ecosystem.
Well-circulated ponds will have consistent water temperatures throughout the system. Monitoring these water temperatures can provide some predictable insight into the aquatic growths that will be developing.
At 50° F the system wakes up from winter dormancy; some signs on new growth develops. Odors may begin to be noticeable. You should begin microbial treatments. Consider adding lake dye if the water is currently clear. Circulation can run as little as 8 hours per day.
At about 60 ° F, aquatic plants and algae are ready to begin active growth. This is affected by nutrient levels, sunlight and weather conditions, turbidity, and level of dye in the lake. You may want to begin light spot treatments of chemicals to keep growths to a minimum, allowing bacteria populations to begin to dominate the system. Circulation should run at least 10 hours per day.
At 70 ° to 74° F, algae and aquatic weeds are actively growing. These growths are still dependant on sunlight and are affected by weather conditions and other factors. As the water temperatures rise, oxygen levels can be reduced, so circulation should be run 10 to 12 hours per day and the aeration system should be run four hours into the night to compensate for oxygen drops at night. Summer water temperatures can maintain a consistent 75° F in moderate climates to as high as 90° in some desert areas. Summer is when heavy growths of weeds or algae can develop and you want to make chemical treatments promptly if aquatic growths begin to develop rapidly. You can effectively treat these plants within the schedule laid out above, if you are ready with the correct treatment, on schedule, when and where it is needed. |