
Most fish keepers do not track the level of nitrates in aquarium water as closely as ammonia and nitrites. This is the reason why the effects of nitrates in aquarium water are not fully understood. Unlike ammonia and nitrites, the effect of nitrates are not as lethal but over time, it will affect the fish, plants and the aquarium environment in general.
What are Nitrates?
Nitrates are a by-product of nitrate conjugation during the late stages of the nitrogen cycle. All aquariums contain a certain level of nitrates. That’s because water used to fill aquarium have the presence of nitrates in it. In the US, drinking water contains as much as 40 ppm of nitrates.
Decayed plants, over-feeding and dirty filters also contribute to the acceleration of nitrates level in aquarium water. In nature, nitrates level is relatively low at 5 ppm. But in freshwater aquarium, nitrate level must be kept at 50ppm at all times. The lower the nitrates level, the better it is for the fish and the plants. If you are breeding fish or is struggling with algae growth, the nitrates level must be kept at a minimum of 10ppm.

The Effects of Nitrates n Aquarium Water
Effects on Fish
When nitrate level reaches 100 ppm, it can make the fish more vulnerable to diseases. The unbalanced nitrates level could also affect the fish’s ability to reproduce, causing some fish to become sterile. Generally, fish exposed to high levels of nitrates are more stressed because of the depleted oxygen level. Young fish exposed to high levels of nitrates will suffer from stunted growth.
Effects on the Water
The elevation of nitrates level also contributes to an overgrowth of algae. In fact, nitrates level as low as 10 can cause undesirable overgrowth. Although aquatic plants are able to absorb nitrates, an overgrowth of algae will deplete oxygen level, killing the plants.
How to Reduce Nitrates Level
Use Filters
A conventional aquarium filter can significantly reduce nitrates in the water. Unlike nitrites or ammonia, bacteria that remove nitrates do not thrive in an oxygenated environment. You can also use special filters to remove nitrates, but these products are more expensive than conventional filtration units. You are better off using a regular one to ensure the right level of nitrates in the water.
Clean the Tank Regularly
To remove algae growth and fish waste, always clean the aquarium regularly. A clean aquarium produces fewer nitrates, helping the fish and plants stay healthy!
Never Overfeed the Fish
Ultimately, waste is the number one cause of high nitrates in aquarium water. Waste from fish is a significant distributor to excess nitrates. Our advice is to regulate the amount of food you feed the fish. Overfeeding the fish could lead to excessive waste like phosphates. Phosphates are compounds that cause excess nitrates in aquatic water.
Add More Aquatic Plants
Aquatic plants do more than just mimic the natural habitat of the fish; it can also reduce nitrates in the water. These plants act as a natural filtration system while boosting oxygen level that will benefit the fish!
