Why are my Nitrates high?

Detritus, decaying plant material, dirty filters, over-feeding, and overstocking the aquarium all contribute to increased levels of nitrate. Additionally, tap water used to fill the aquarium may contain nitrate in it. In the United States, drinking water may have nitrates as high as 40 parts per million (ppm).Click to see full answer. Also asked, how do you fix high nitrates in an aquarium? Add live plants to a freshwater aquarium. Plants naturally utilize nitrate as a nutrient and food. Reduce fish population or upgrade to bigger tank. Cut back on feeding. Use a nitrate remover such as ALGONE. Subsequently, question is, what do high nitrates do to fish? Although far less toxic than ammonia or nitrite, high nitrate levels—called nitrate poisoning or nitrate shock, can also kill aquarium fish. Nitrate is one of the natural byproducts of fish digestive tracts and will build up in any tank that is not properly maintained. Furthermore, why are my nitrate levels high? Overfeeding is the number-one cause of high nitrate levels in aquariums. Overfed fish produce much more waste than normal, and when more food is given than they can take in, the uneaten food rots and produces even more wastes. Keeping too many fish in a tank also leads to problems with accumulated wastes.What causes nitrate in fish tank?Nitrate is a bi-product of ammonia, which is a common waste product found in fish tanks. It comes from fish waste, old food and plants in the water. Since ammonia is highly toxic to fish, the biofilter in your fish tank is designed to break it down into components that fish are more resistant to.