how often should I change out my pre-filter?

[ringwurm]

I'm using a chunk of prefilter material in my sump to catch the big particles in the water. How often do I need to change this out? I hear they can become nitrate factories if they are left in too long. I have been changing it out once a week. Can I go longer?

 

[FishGuy818]

every 3 months is what i do

 

[steve-s]

Instead of changing it out weekly, try rinsing it with tank (or RO if not a biological source) water instead. It should remove much of the trapped detritus and allow you to extend the life of the material. You can then simpley discard the waste water. Easiest way to determine if it's working is by testing water quality.

Cheers
Steve