Pond Management – Nitrates are a natural by-product of animal waste and fish. Bacteria convert fish waste into ammonia that turns into less harmful nitrates. That is then born-again into nitrates that prey on protoctist and alternative microorganisms. Excess nitrate in the pond will cause it to become cloudy with algae and could damage the fish in the pond. The management of nitrates in the pond is an ongoing maintenance task, but work can be minimized with a variety of filtration methods.
Monitor your pond visually. If the water is cloudy or if you notice the excess growth of algae, your nitrate levels are probably high. This is a result of the natural cycle of nitrogen. In natural ponds, there are enough plants to consume the excess nitrates and keep the water balanced. Many garden ponds are very populated with fish instead of plants, which can lead to an accumulation of nitrates.
Purchase a pond water test kit. Make sure the kit you buy test specifically for nitrates. Many basic pond test kits only test the pH of the water, or test pH and ammonia levels like these are the two elements most likely to be toxic to fish. Follow the manufacturer’s directions to check your pool water for nitrates. Typical ponds have nitrate levels of between 50 and 100 parts per million (ppm). Nitrate levels of up to two hundred ppm are usually acceptable. Perform a water test every two to four weeks to control the levels of nitrate in your pond.