Filter question

[rhance]

I have a 5 gallon nano tank, when should I change the filter if ever? Its a foam block, carbon insert, and biomax insert

 

[Bryce M.]

I'd say every month or so, two at the very least. Even if you don't have a lot of bioload it's not a bad idea having good filtration no matter what, especially on a pico tank where things can go bad quickly

 

[BeejReef]

+1

The alternative is a strict testing schedule to determine when they're exhausted. Filters cost a lot less than even two test kit refills.