Now that you have the pond you have always wanted it is time to think about providing the ecosystem it deserves. This will not only keep your water garden clean and promote a self-maintaining pond; it will provide a healthy habitat for fish, turtles, butterflies, birds, frogs, newts and salamanders, aquatic plants, and dragonflies (which help to control the mosquito population!). Let's cover the basics to ensure vibrant fish in an ecologically sound habitat: your pond!
Clean, healthy water is critical to fish health. A proper filtration system includes the use of mechanical and biological filters. The Mechanical filtration removes particles and is, for our clients, primarily handled by a skimmer. This will not only pre-filter the water and house the pump; it will also skim the water's surface to prevent the accumulation of organic materials on the pond floor. Biological filtration reduces and keeps the fish from swimming around in their own waste. Plants are key to your pond's biological filtration (water hyacinths are great for this, but all aquatic plants will contribute) as is the beneficial, aerobic bacteria.
Aquatic Plants are Mother Nature's best filters - from a filtration perspective they are second to none. Thriving from the excess nutrients in a pond and depriving the algae of its food source, the aquatic plants in a water garden, given proper coverage, are critical to the overall ecosystem. It is not a good idea to keep more than one pond plant in its container (and none for ponds 8'x11' and larger) because aquatic plants need to stretch their roots in order to thrive, and because those roots will help to reduce bio-solids, or sludge.
Aerobic bacteria are very efficient in breaking down waste products. The aerobic bacteria that Jefferson Landscape and Design introduces after we install your pond, colonizes in the rocks and gravel. These are tremendous surface areas for the bacteria to break down excess nutrients in the water and dissolve organic debris (like fish waste) on the pond floor. The bio-waste from the bacteria is then taken back up as nutrition by the plants.
Fish are an integral part of any ecosystem and contrary to popular belief, fish will actually reduce pond maintenance. However, overstocking and overfeeding pond fish is a serious, common mistake. Fish love “crowds” but your pond's water quality cannot be sustained if the population is too dense. Overstocking creates water quality issues causing the ammonia in the pond to go up.
All fish have a certain level of parasites; likewise, all water gardens have a certain level of bad bacteria – this is normal and both have their respective functions. However, ammonia nitrates can throw these levels off and affect your ponds balance and the health of your pond fish. Ammonia spikes can burn the gills of your fish and kill them. Ammonia nitrates also promote the growth of string algae. A healthy water garden has approximately one inch of fish for every 10 gallons of pond water (120 inches = 1200 gallons); assume your fish's maximum size when calculating.
Lower temperatures decrease the metabolic rate of fish. When your pond water reaches a temperature of 50 degrees or lower, stop feeding your pond fish until the temperature returns. Goldfish and plecostomus do not need to be fed; goldfish, plecostomus (and Koi) will eat the algae in your pond and help to complete the ecosystem. By feeding goldfish (or plecostomus) you are essentially removing them from the ecosystem and throwing it off balance. Clients who do this are no doubt purchasing algae products they would otherwise not have to. Plecostomus is a great bottom feeder!
Koi need to be fed, and if you feed your Koi from a consistent location your Koi can be conditioned to be rather friendly! If you purchase Koi for your pond, feed them every other day for about 2-3 minutes, then stop. Do not feed them every day! Avoid corn meal in your Koi food, and instead seek “fish meal” or other fish protein as the first ingredient on the label. The protein content should be between 35-40%. Color enhancers are also good (spirulina, canthaxanthin), and a stabilized Vitamin C is crucial. If you leave for vacation, Koi will help the other fish nibble on the algae and both will work to give you a maintenance free water garden!