In nature, the nitrogen cycle is done automatically where the nitrogen goes from air to plant to bacteria and then again to air. In this process, human intervention is not required. But the fish tank is different. Here, you have to do the nitrogen cycle almost manually.

Nitrate is an odorless and colorless gas that is created by aquarium waste such as uneaten food, fish poop, dead plant, dirty filter, etc.  

When nitrates become too high in your aquarium, they can have detrimental effects on your fish, such as reduced growth, lethargy, stunting, and fin rot. Some fish are hardier than others, but you still need to keep an eye on your nitrate levels. 

Fortunately, many tools, tests, and methods are available to help you check your nitrite levels.

How Long for Nitrites to Go Down

How long for nitrites to go down? It usually takes 2 to 6 weeks to get nitrites down from the aquarium. If you want to lower nitrates from your aquarium, you need to perform some additional tasks. These are adding plants, nitrifying bacteria, water conditioner, partial water changes, avoiding overstocking, controlling overfeeding, etc.

Nitrites can accumulate in fish tanks over time and make water murky and harmful for fish. Fortunately, you can easily remove nitrates from the water with a filter that removes nitrates and nitrites. 

The removal of these substances is crucial in protecting fish health. Still, fish tanks store elevated levels of nitrogen that can eventually harm fish, so you’ll want to test the water and track any changes. 

Nitrites are a life-threatening poison for the fish and plants created by ammonia. Ammonia is another pollutant and is more harmful than nitrites. It is released as a fish excrete through the fish’s gill and converted into nitrite by the beneficial bacteria. In a healthy aquarium, nitrites are converted into nitrates tolerant to fish and less harmful.

Fish tanks that are newly established or uncycled yet can produce more ammonia because beneficial bacteria might have no time to grow to detoxify the waste from the tank. As ammonia and nitrite come from fish waste, you may think your empty tank is safe from toxicity.

. But the reality is that ammonia and nitrites are elevated at any time. As soon as the ammonia level is raised, the nitrite level will also rise and put your fish at risk.

How Long Does a Nitrite Spike Last?

A nitrite spike is just what it sounds like—a sudden spike in ammonia that can create nitrite spikes. It is a sign of poor water conditions, and this can happen for several reasons: an algae bloom, overfeeding, insufficient water changes, broken filters, and overstocking. 

It is a common problem in many aquariums and reef tanks, and it can happen to just about any tank. 

But did you wonder how long a nitrite spike lasts? 

Nitrite can be stuck for a period of time, and the spike can last about 2 to 3 weeks before converting into nitrates. When the temperature drops below 70F, the spike may stay for a longer time.

What Is the Ideal Nitrite Level in a Fish Tank?

Between 0 to 0.2 ppm (parts per million) is generally considered a good level of nitrite in an aquarium. For many fish, the ideal nitrite level is 0 ppm.

In the freshwater aquarium, the ideal nitrite level is 50 ppm at all times, and good to keep it below the 25 ppm. Any value that is above 50 ppm is harmful to freshwater fish. 

When it comes to saltwater tanks, the maximum amount of nitrite can handle is 5 to 10 ppm. The presence of nitrites over 5 to 10 ppm indicates something wrong with your aquarium.

What about a reef tank? The nitrite level should be kept at 0.25 ppm or 200 ppb in the reef tank. But more than 5 ppm is harmful to your fish and corals. Any measurable value above 5 ppm might be life-threatening for sensitive fish and other creatures.

If you notice the nitrite level of your tank is above 1 for a longer time, you should keep a close eye on your tank because it is not yet appropriately cycled.

What Causes High Nitrate Levels in Aquariums?

• Improper nitrogen cycle
• Overfeeding 
• Lots of fish in less space
• Broken filter
• Dirty substrate
• Clogged equipment
• The leak of proper maintenance
• Stay away from water checking
• Not to perform partial water changes
• New aquarium setup
• Excessive waste