Cloudy Water

[westonsupermanc]

I recently put an external filter on my 480l tank and 3 weeks on the water has gone cloudy. I am not suggesting it is the filter maybe it is something else I have not done. Any ideas please?

 

[Stimo]

did you use old filter media in new filter?
 
sounds like a  bacterial bloom of some sort maybe?
 
usually happens through cycling

 

[Ninjouzata]

Did you take another filter off or just add one? Did you rinse the media that came with it?
 
What are your water parameters?

 

[wolfwood2186]

To me it sounds like a bacterial bloom.  This usually happens in new tanks.  It will go away on its own in a week or two.

 

[rms]

You may have triggered a mini cycle, or indeed a full cycle, depending on how you changed the filter. If you didn't use the old media then most of the bacteria is lost and a full cycle has started. If you only get bacterial blooms in new tanks to me that sounds like you have ammonia spikes so water changes might be needed. Test your water and take necessary action. If it's a mini cycle it won't take long to sort it out, but leaving it to right itself might not be the best course of action.

 

[Meeresstille]

Checking your parameters is a good start. Did you keep the cycled filter media from the old filter on the tank? 
 
Is the water looking milky or more like a green tint. 
White, milky cloudiness is usually a bacterial bloom, green suggests algae.
Does your tank get direct sunlight? How long do you keep the lights on?
 
Sometimes tiny bubbles from the filter can make a tank look cloudy, or debris from unwashed filter material. If you had washed the filter material before adding it, you could check if the filter is causing tiny air bubbles.