Cloudy Aquarium Water: Causes and Solutions

Cloudy Aquarium WaterHaving cloudy water aquarium has surely been experienced by hobbyists at one time or another. This phenomenon can take place in both an established or a new aquarium.

The earliest sign that there is something wrong in your tank can be detected by looking at the water. In a well-balanced aquatic ecosystem, the water should be clear. If the water appears to be cloudy, this should tell you that something is not working as it should be.

Reasons for Cloudy Water in Aquarium

There are several important reasons for the cloudy water appearance in fish tanks:

  1. Bacterial Bloom
    In new tanks that has not been fully cycled, the existing biological filter is not enough to remove excess ammonia from the tank water. This creates a good medium for bacteria to start building up in the tank, a phenomenon commonly referred to as “bacterial bloom”. Water is an excellent medium for bacterial growth and multiplication. The bacterial population in a fish tank is composed mostly of beneficial microorganisms that play an important role in aquarium cycling. Bacteria help breakdown waste products of fish and plants. There are instances when there is a sudden change in any of the water parameters, creating ideal conditons for the increase in the rate of bacterial multiplication, making your water appear cloudy. Among the popular reasons associated with this situation is the addition of new fish to the tank, as well as making unexpected changes to the aquarium filter’s bio-load.
  2. Insufficient cleanng of new substrate
    When new substrate is added, it is recommended to clean the substrate thoroughly before putting into the tank. However, even with cleaning, there will always be a bit of dirt that remains with the substrate which is bound to cause a bit of cloudiness in the tank water. However, as things settle down, your water will be clear in a day or two.
  3. Switching off the filter at night
    There are newbies who want to save on electricity by switching off the filter during nighttime. However, this is a major mistake that can cost you your biological filter. Without an efficient biological filter, you will need to cycle your aquarium water all over again. Switching off your filter system for too long will certainly pave the way for cloudiness inside the tank.
  4. Washing biological media in tap water
    Tap water contains chemicals (i.e. chlorine and chloramine) that water companies have added to make water safe for drinking. When you use tap water for washing your biological media, you will be killing the beneficial bacteria, requiring you to cycle your tank over again.
  5. Using certain medications
    Some medications have chemicals that can kill your biological filter. One common example is methylene blue which is often added to tank water to eliminate fungus growing on fish eggs. If you need to add certain medications to your tank, be sure to read the instructions carefully.
  6. Making a large water change without using water conditioner
    When you need to make a large water change, you should always add water conditioner when adding tap water to your tank.

About the Author:

Peter Hartono is the founder and CEO of Just Aquatic - a proud Australian company that offers homegrown aquarium supplies and tropical fish tanks of all kinds carrying top of the line brands including API, biOrb and Exo Terra.