Your Fish Tank: Understanding Aquarium Parameters


What the heck are water parameters?!

Water parameters are measurements of sustainable levels that allow your fish to thrive in an ecosystem. 

In fish keeping, parameters we mainly discuss are Temperature, Ammonia, Nitrates, Nitrites, pH, KH, and GH.

Temperature: The water temperature that allows a fish to live happily.

Ammonia (NH3): Ammonia is formed from the metabolism of protein and is the major waste product of fish. The majority of ammonia from fish is excreted through gills, little being lost through urine and feces. Ammonia is also formed as uneaten feed or other organic matter in an aquarium decomposes.

Nitrates(NO3)Nitrate is a by-product of nitrite oxidation during the later stages of the nitrogen cycle. It is "generally" present all aquariums. Detritus, decaying plant matter, dirty filters, over-feeding, and overstocking the aquarium all contribute to increased levels of Nitrate biproduct from Nitrites. Unlike Nitrites, Nitrates are not toxic in low levels. However with higher levels of Nitrates, expect to see an increased reading of Nitrites. This is not a good sign and requires immediate care.

Nitrites(NO2): are a naturally occurring chemical in your aquarium that is created through the breakdown of ammonia by bacteria in your biological filter as part of the Nitrogen cycle. The main causes of high nitrite are: new biological ecosystems, damaged or depleted biological ecosystem, over stocking your tank, and over feeding.

pH: This indicates whether your aquarium's water is acidic or basic. The pH scale ranges from 1-14. Values below 7 indicate acidic water, a value of 7 means your aquarium is neutral, and values above 7 means your aquarium water is Basic (alkaline)

KH (Carbonate Hardness): KH measures the concentration of carbonate (CO3²⁻) and bicarbonate (HCO3⁻) ions in the water. It acts as a buffering agent, helping to stabilize and maintain the correct pH levels in the aquarium.

GH (General Hardness): Is a reference to how hard or soft the water is. Freshwater contains lots of dissolved minerals it is described as hard, and if it is low in minerals or devoid of minerals altogether it is known as soft.


Over time with established aquariums, you should only see Nitrates rise, the population of beneficial bacteria will be strong enough to breakdown the ammonia and nitrites into nitrates. Be aware that beneficial bacteria is only introduced through adding it into the aquarium yourself through properly starting your ecosystem with bacteria starters and "ghost feeding".

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