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Testing Your Aquarium Water – Guide to Essential Water Parameter

19 06, 2023

Aquarium water condition - Why is it so important?

Water is crucial for the aquarium's health. All the essential components for aquatic creatures can be found here. Many substances that allow them to live and grow are provided by water. That's why you need to pay attention to regular water-testing.

The correct level of parameters in the aquarium

The right balance of parameters is a key for the wellbeing and health of aquatic animals. Too high or too low values of certain elements can lead to diseases, stress, and even death for all organisms in the aquarium.

When are the ideal parameters? The answer 'it depends' should come as no surprise. The appropriate values for the organisms in the aquarium will vary depending on the types of organisms. The conditions in a marine aquarium will be different from those in a freshwater aquarium.

pH level

The pH of water determines its acidity or alkalinity. The pH of the aquarium with freshwater fish and plants should be between 6.0 and 7.0, which is slightly acidic. On the other hand, the pH scale in marine aquarium shouldn't be higher than 8.0-8.4. That is the ideal pH for marine animals in a natural environment.


NH3 is extremely toxic to fish. The decomposition of nutrients, fish waste and other organic pollutants results in ammonia. Just a small amount of ammonia is enough to destabilise the biological balance in the aquarium. As a result, this leads to disease and even death of the animals. Monitoring ammonia levels frequently is important to prevent them from rising dangerously.


NO2 is a product of the second stage of the nitrogen cycle, which begins with the breakdown of ammonia by nitrifying bacteria. The presence of NO2 in the water signifies the beginning of the purification process, despite its toxic nature. Even slightly elevated nitrite levels should not be ignored in a properly balanced aquarium. This can be a sign of problems with the biological balance.


Nitrate is the least toxic compound in the nitrogen cycle. It is the product of the third stage of this cycle. The presence of nitrate in the aquarium water is a good indicator of a properly functioning biological system. The nitrate levels in tank water depend on the type of aquarium and the species living in it. Too high a concentration of these compounds can contribute to algal growth.

Carbonate hardness (KH)

Carbonate hardness (KH) is an indicator of the water's ability to buffer acidity and maintain a stable pH in the aquarium. KH depends on the content of calcium and magnesium bicarbonates, boron carbonate. The recommended KH level in a marine aquarium is 6.5 - 8.0 dKH.

General hardness (GH)

The amount of calcium, magnesium, and other metal ions affects general hardness. These compounds are poorly soluble and can form a lime deposit on aquarium components, especially in areas where water flow is increased. The hardness of the water should be kept in the right range to ensure ideal conditions for our aquatic friends. The range for most species is usually between 3 and 20 total hardness units (dGH), but the ideal value depends on the animals environment.

Testing water parameters in aquariums

click and discover the best method for water parametr testing

When and how to test aquarium water? Regular checks of the aquarium parameters are necessary. Monitoring the water continuously allows for the early detection of any negative changes in water chemistry. It allows to quick reaction and solutions to chemical balance problems in the aquarium. This is why you need to test your water regular. The main aquarium water parameters you need to test are pH, carbonate hardness (KH) and total hardness (GH). Nitrate, ammonia and nitrite test should also be performed. We recommend using our nitrate test.

The parameters that help determine which components are too few in a planted aquarium are the most important parameters. The levels of nitrate, phosphate, and iron are the most important parameters to control.

In case of reef aquariums, one of the most important things to do will be measuring the concentration of nitrogen and phosphate compounds. If you are keeping corals in an aquarium, you need to provide them with the right amount of micro and macro elements. Aquaforest Lab's advanced water tests and wide range of supplements, available from Aquaforest Lab, create an easy system to maintain optimal conditions for aquarium inhabitants.

To keep the healthy tank, remember about regular water changes. It is also good practice to test RO water.

Aquarium water tests

Much water testing kits can be found on the market. Among the main water testing methods, we can mention:

Strip tests

It is an easy-to-use tool for measuring water quality. These tests consist of a strip with a reagent, which changes colour depending on the value of the parameter under test. Test strips are most commonly available to measure aquarium pH, water hardness, ammonia, nitrite, nitrate, phosphate and chlorine.

Drop tests

It is one of the most popular methods of water testing. These tests allow the level of various chemicals in the tank water to be determined with a high degree of accuracy. In our offer you can find drop test as: Magnesium Test Kit, Alkanity Test Kit, Phosphate Test Kit, Nitrate Test Kit, Calcium Test Kit. Water drop tests involve adding special drops of reagent to a water sample and then observing the change in colour of the water.

ICP-OES tests

Considered by most to be the best aquarium test kit. It is a highly advanced technology that allows a high accuracy, while also testing for the presence of micro and macro elements, alkanites and environmentally harmful substances. Aquaforest Lab uses a top-quality spectrometers to provide accurate and detailed water composition results. Advanced analysis can determine whether the water contains harmful substances or requires additional replenishment. The test results help to choose the right aquarium management, clearly indicating surpluses and deficiencies of individual elements in the fish tank.

test your tank water


Suitable aquarium water parameters depend on the species of fish and the requirements of other organisms. Therefore, there is no one simple answer to the question of what parameters are best. It is important to adapt the conditions in the aquarium to the species of animals in it. It is necessary to observe the basic parameters and regularly check the water quality in the aquarium to ensure ideal conditions for the animals and plants.

Order an ICP test on our website www.aquaforestlab.com, send us your samples and take the best possible care of your aquarium.