How Often Should You Change The Filter ?

[MarcusTheGreat]

title says it all

[Draug Isilme]

Well, it varies from person to person. So long as you don't do it too often and give beneficial bacteria time to grow on it, you can just change it whenever it starts to wear out. If You'd rather change it sooner, then I suppose every month or two or more- although it seems like it'd be kinda costly in the long run if you changed it every month, but that's just my opinion ^.^ Also, when you change filters, if you'd like the beneficial bacteria to grow faster on your new filter media, then you can just cut a good sized piece and stick it back in your filter- helps to cycle faster.

[kfryman]

I would say not to change your filter very often unless it is destroyed. This is where a lot of beneficial bacteria is stored so try to keep changing to a minimum.

[Bombalurina]

+1. Every time you change it, you kill the good bacteria in it and restart the cycle. Unless it is falling apart and you have cycled media ready to go in it, don't change it.

[kathstew]

As everyone else said.
If you do replace it, I would put a sponge or something in the tank for a few weeks before replacing the filter. The sponge will build up with beneficial bacteria, allowing the re-cycling of the tank to go a lot faster.

[Myates]

Carbon filters should be changed once a month-
Sponge filters replaced when it is falling apart-

To clean out the sponge media in both the carbon and sponge filter, remove it during a water change and swish it in old tank water (water you just removed from the tank during cleaning) to remove the sponge of debris- and then place back into the filter.

When having to replace the sponge part of either filter type, add in the replacement a week or two prior to changing it out to give it time to build up the proper bacteria. Normally you only have to replace the sponge once, maybe twice a year, and sometimes not even then but longer.

Gravel will hold a lot of the beneficial bacteria, so your tank won't have to cycle itself when you replace a filter media such as the carbon- and normally there is a sponge part in the carbon filters as well.