It's important to pay attention to your aquarium water's clarity. Often there's nothing to worry about, but cloudy water can be the first sign of harmful water conditions. Thankfully, while your fish tank can get murky for a number of reasons, most cases of cloudy water have very easy solutions.
If you have recently changed the water in your aquarium, the water may be cloudy for a day or two. When new water is added to the tank, particles in the rocks and on the plants might become dislodged and float in the water. The cloudiness will soon dissipate, and the water will be clear again.
Filters are built to service aquariums of a particular size. Often a filter can become overloaded if it is too small for your aquarium, or if the tank is overcrowded with fish. Check the filter's capacity according to the manufacturer. If your filter is the right size, make sure its cartridge is fresh and clean.
Every new aquarium experiencing "cycling," which may take between six and eight weeks. As new organisms settle into life together, the tank can look murky or cloudy. This is called a "bacterial bloom" and may resurface from time to time, even in a mature aquarium.
A well-established aquarium with live plants can experience an overgrowth of green algae or other organic material. While green algae is not harmful to your fish, it can certainly be unsightly. To prevent this overgrowth, make sure that the tank is not sitting in direct sunlight, and don't leave the aquarium lights on for more than eight hours a day.
- Jochen Sands/Digital Vision/Getty Images