The fastest way to lower nitrates in an aquarium is to perform a large water change with dechlorinated water that has low or zero nitrate levels. This will instantly dilute the concentration of nitrates in the tank and improve the water quality for the fish and plants. However, water changes are not a permanent solution, as nitrates will build up again over time due to the natural nitrogen cycle. Therefore, it is important to understand what causes high nitrates in an aquarium and how to prevent them from reaching dangerous levels.
What are nitrates and why are they harmful?
Nitrates are chemical compounds that contain nitrogen and oxygen. They are the end product of the nitrogen cycle, which is the process of breaking down organic waste (such as fish poop, uneaten food, dead plants, etc.) by beneficial bacteria in the aquarium. The nitrogen cycle consists of three stages: ammonia, nitrite, and nitrate. Ammonia and nitrite are highly toxic to fish and can cause death in high concentrations. Nitrate is less toxic, but still harmful in excess.
High nitrates in an aquarium can cause several problems, such as:
- Algae growth: Nitrates are a source of nutrients for algae, which can quickly take over the tank and make it look unsightly. Algae can also reduce the oxygen levels in the water and compete with plants for light and space.
- Fish stress: Nitrates can irritate the gills and skin of fish, making them more susceptible to diseases and parasites. Nitrates can also affect the immune system and the reproductive system of fish, reducing their lifespan and fertility.
- Plant deficiency: Nitrates are one of the macronutrients that plants need to grow, but too much nitrate can cause an imbalance in the nutrient ratio and lead to plant deficiency symptoms, such as yellowing, curling, or wilting of the leaves.
How to test and monitor nitrates in an aquarium?
The best way to test and monitor nitrates in an aquarium is to use a liquid test kit that measures the nitrate level in parts per million (ppm). Test strips are less accurate and reliable, and should be avoided. Ideally, the nitrate level in a freshwater aquarium should be below 20 ppm, and in a saltwater aquarium below 10 ppm. However, some fish and plants can tolerate higher levels, depending on the species and the tank conditions.
It is recommended to test the nitrate level in the aquarium at least once a week, or more often if there are signs of high nitrates, such as algae growth, fish stress, or plant deficiency. It is also advisable to test the nitrate level in the tap water or the source water that is used for water changes, as some water supplies may have high nitrates due to agricultural runoff, sewage, or industrial waste.
How to lower nitrates in an aquarium naturally?
Besides performing water changes, there are other natural ways to lower nitrates in an aquarium, such as:
- Reducing feeding: Overfeeding is one of the main causes of high nitrates in an aquarium, as it leads to more organic waste and more nitrate production. Therefore, it is important to feed the fish only as much as they can eat in a few minutes, and remove any leftover food from the tank. Feeding less often, such as once a day or every other day, can also help reduce nitrates.
- Increasing filtration: The filter is the main site of the nitrogen cycle, where the beneficial bacteria convert ammonia and nitrite to nitrate. By increasing the filtration capacity and efficiency, more nitrates can be removed from the water. This can be done by adding more filter media, such as sponge, ceramic rings, or bio balls, or by upgrading to a larger or more powerful filter. The filter should also be cleaned regularly, but not too often or too thoroughly, as this can disturb the beneficial bacteria and cause a spike in ammonia and nitrite.
- Adding plants: Plants are natural nitrate removers, as they use nitrates as a source of nitrogen for their growth. By adding more plants to the aquarium, especially fast-growing ones, such as hornwort, duckweed, or water lettuce, the nitrates can be reduced and the water quality can be improved. Plants also provide oxygen, shade, and shelter for the fish and other inhabitants of the tank.
- Adding algae eaters: Algae eaters are fish or invertebrates that feed on algae and help control their growth. By adding algae eaters to the aquarium, such as plecos, otocinclus, snails, or shrimp, the nitrates can be lowered indirectly, as less algae means less nitrate consumption. However, algae eaters also produce waste and nitrates, so they should not be overstocked or relied on as the sole solution for high nitrates.
- Adding denitrifying bacteria: Denitrifying bacteria are a special type of bacteria that can convert nitrate to nitrogen gas, which escapes from the water. These bacteria are anaerobic, meaning they live in low-oxygen environments, such as deep within the substrate or the filter media. By adding denitrifying bacteria to the aquarium, such as in the form of supplements, pellets, or pads, the nitrates can be lowered significantly. However, these bacteria may take some time to establish and work effectively, and they may also compete with the beneficial bacteria for space and resources.
Conclusion
Nitrates are a common and inevitable problem in aquariums, but they can be controlled and reduced by following some simple steps. The fastest way to lower nitrates in an aquarium is to perform a large water change with dechlorinated water that has low or zero nitrate levels. However, this is not a permanent solution, as nitrates will build up again over time due to the natural nitrogen cycle. Therefore, it is important to understand what causes high nitrates in an aquarium and how to prevent them from reaching dangerous levels. Some of the natural ways to lower nitrates in an aquarium are reducing feeding, increasing filtration, adding plants, adding algae eaters, and adding denitrifying bacteria. By implementing these methods, the nitrates can be lowered and the water quality can be improved for the fish and plants in the tank.