ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Understanding Water Quality In Your Aquarium

Updated on December 4, 2015

What Is Water Quality?

Water quality refers to the state of nitrates, nitrites, ammonia, and water hardness, among other things. This becomes particularly important when attempting to maintain a healthy home aquarium. Unbalanced water can lead to headache and heartache by causing algae blooms, cloudy water, or death of fish. Thus, it is vital to learn everything you can about water quality in order to be a successful aquarium owner!

Ammonia (NH3)

When you feed your fish it inevitably becomes waste at one point or another.A large portion of this waste is ammonia, which is toxic to fish and other aquarium inhabitants even at low levels. This is where your filter comes in--its primary purpose being to house bacteria that can convert ammonia into nitrites. A successful filter will adequately break down the ammonia until the levels are safe. In new aquariums, however, the water must be sufficiently cycled in order to build up these vital bacteria or you will see a spike in ammonia. Even established aquariums can experience ammonia spikes due to an imbalance in the ecosystem, which makes it extremely important to monitor water quality consistently. Ammonia should ideally be below 0.01 ppm (parts per million) but many fish can cope with up to 1ppm of ammonia for short periods of time. If ammonia levels rise beyond that, however, further action may be needed.

Ammonia Molecule
Ammonia Molecule

Nitrite (NO2)

Once ammonia is converted to nitrite it is still dangerous to fish, but not as toxic as ammonia itself. Since nitrite is derived from ammonia, its causes are the same (new aquarium that has not been cycled, too much feeding/waste, etc.). Nitrites should ideally be around 0ppm, but most hardy fish will survive with up to 4ppm. The sensitivity to nitrites depends heavily on the species of the fish, but all fish will succumb to negative side effects if nitrites are elevated for extended periods of time.

Nitrate (NO3)

The final stage of the nitrogen cycle is the conversion from nitrite to nitrate. Nitrates are far less toxic than either of the other forms but of course can become dangerous at high levels. One side effect of elevated nitrate levels is a decrease in immunity, which means your fish can look perfectly healthy but quickly become ill if exposed to diseases. Most fish will thrive in water with nitrate levels up to 50ppm, or even 100ppm for very hardy fish. Of course it is best to keep levels as low as possible, however, to ensure long term health.

What To Do If Ammonia, Nitrite, or Nitrate Levels Spike

If you notice a spike in the levels of ammonia, nitrite, or nitrate in your aquarium, you have a few options to deal with the issue. Partial water changes are the obvious first step, and should be done regularly regardless. Diluting the water in your aquarium can give it a chance to process these pollutants on its own, but ensure that the water you are adding is clean as well. Often times tap water already has high levels and therefor will not help the situation at all. Secondly, adding live plants to your aquarium can help combat these issues. If neither of these solutions help, there are many commercial additives you can use to lower your levels of ammonia, nitrite, and nitrate.


pH can be a difficult thing to manage. It is important to the overall health of your aquarium, but different species prefer different pH levels and tap water in different areas will differ as well. To gain a basic understanding of pH it is important to realize that it is merely a scale of how acidic or alkaline the water is. pH below 7 is considered acidic while over 7 indicates alkaline. The ideal pH level is generally between 6 to 8, but more specifically 6.5 to 7.5 for the vast majority of species. If your water falls out of this range you may begin to experience issues, and will need to either alter the water or only stock fish that thrive in your pH range. The easiest way to combat this is regular water changes which will sufficiently replenish the natural minerals that buffer the pH. Commercial additives can also be purchased but should be used with care and caution.

Water Hardness

The terms hard or soft water refer to the amount of salt and minerals that it contains. Low levels of salt and minerals are considered soft, while high levels are considered hard. It is closely linked to pH since the same minerals that buffer pH levels are included in the overall water hardness. Hard water with many minerals can absorb the acidic substances and prevent drops in pH, which is why hard water is often assumed to be alkaline. Similarly, soft water is generally acidic. Again, different fish species prefer different hardness levels, so it is important to take this into consideration when stocking a tank. For most aquarium owners water hardness will never become an issue if regular water changes are performed, but it should be noted that soft water can be more prone to potentially fatal pH fluctuations and thus should be monitored more closely.

What Now?

These are the BASICS of water quality and should by no means be considered a comprehensive guide. Aquarium owners should take great care in educating themselves on this topic in order to ensure a successful aquarium experience.


    0 of 8192 characters used
    Post Comment

    No comments yet.