Water slightly cloudy

Question
Hi Sean,

I wonder if you can help me.  I have 2 common goldfish in a 40-gallon (180 litres) aquarium.  The aquarium has been set up since September last year.  The ammonia level is zero, the nitrite level is zero, the nitrate level is 5ppm and the PH is 7.4.  I do regular weekly water changes of about 15%.

The problem is since last week I have noticed the water in the aquarium is not as crystal clear as it should be.  It's only very slight cloudy or hazy looking.  I have two filters in the aquarium which I checked and both are working normally.  All my water parameters are fine too so what could be causing this?  Any ideas?

Answer
Katie,

Cloudy water is due to one of two things, algae bloom or bacteria bloom.  Both are caused by too many nutrients in the tank.  White cloudy is bacteria and green cloudy is algae.

Here is a great article on cloudy water:   http://www.aquaria.info/index.php?name=News&file=article&sid=377


Sean
Owner - FishGeeks.com