How to test Aquarium Water Quality? Complete Guide


Is it necessary to learn how to test aquarium water quality? The one-word answer is yes. In the newly set up aquarium, it is essential to test the water quality to avoid fish loss because the ammonia and nitrite rise in water.

In a newly established aquarium, it is necessary to test the water quality for the health of your fish. Hence, water testers are essential for setting up an aquarium.

If you are not comfortable with water testing yourself, you must consult the nearest fish shop for water testing. This guide will discuss the importance of testing water quality and some essential testing kits.

Best Aquarium Water Test Kits 2021

To learn how to test aquarium water quality, you must know about the best aquarium water test kits. Ammonia, pH nitrite, and nitrate are the most important testing kits for water quality testing of an aquarium.

You can use a digital aquarium water tester for your convenience, but you can't use them for giant aquariums. Keeping a log of all aquarium testing will help you stay informed.

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The key things to look into water for the safety of your fish are ammonia, nitrite, pH, and nitrate. Keep reading; we will discuss each of these in detail.


The number one killer of the fish in the fish tank is ammonia. It develops in the new tanks rapidly, but if the tank's water is not changed regularly, it can be elevated there too.

If the filters are not clean, water is not changed regularly; the tank is overstocked or overfed, then ammonia can increase the water toxicity. Therefore, in a set aquarium, an ammonia test should be conducted every week.

In addition, if you find any sick or dead fish in the tank, immediately conduct a test with the aquarium water testing kit of ammonia.


In the startup of the new aquarium, the nitrite level can soar and kill your fish. Even after the initial cycling of water, it can soar the water level and cause trouble.

Due to that reason, you should conduct the nitrite test with an aquarium water testing kit every month. Elevation in nitrite must be considered a sign of danger.

It would be wise if you conducted a quick nitrite test if any fish died in your aquarium. If you see elevated nitrite levels in aquarium water test kit results, quickly changing the water or adding a low salt level can reduce toxicity.


The fish cannot tolerate the sudden changes in the pH of the water. Even only 0.2 sudden changes can kill the fish instantly. Therefore, it is a most overlooked parameter in aquarium testing.

Water's acid-base balance is determined by its pH. As mentioned above, it is the most frequent cause of fish stress, leading to rapid fish loss.

Water hardness, plants, and fish waste topping off water, and water evaporation all of these things can lead to changes in the pH.

Therefore, the pH of a fish tank should be tested at least once each month or whenever the fish dies.


The nitrate in the aquarium is not as toxic as nitrite or ammonia. But nitrate should be monitored regularly to avoid the stress of fish. In addition, the algae problem can be caused by nitrate.

The only way to eliminate nitrate from the tank is through water changes. Therefore, monthly tests are highly recommended in the tanks, mainly when fish are breeding. As compared to adult fish, young fish are more sensitive to nitrate.