Filter Help

[mbeer21]

I'm looking for advice about my filter; I'm not sure how often I'm meant to change the filter media, if at all.
My old filter on my smaller tank had a carbon/wool cartridge, a filter pad and a sponge, and I just replaced the cartridge occasionally.
This new filter is an Aqua One Clear View Hang-on-back. It has a carbon/wool cartridge first and then something called a bio-grid behind it that's supposed to collect beneficial bacteria. I imagine I should never clean that, as icky as it's gotten, but how often should I replace the cartridge? I was told I didn't need a sponge in there due to the grid (I don't understand that logic, but there you go) but I might be able to squeeze one in there if it would help.
Tank is 130L and the filter is supposed to be fine up to 150L (but I'd be happy to upgrade if this still isn't enough). Stock is listed in my signature

 

[raptorrex]

I would change the carbon pad when flow drops. thats after you have tried to wash it. you may find a good rinse will keep it good, until the next clean.

you should rinse your "bio media". but do it in tank water. then replace it.

 

[mbeer21]

I would change the carbon pad when flow drops. thats after you have tried to wash it. you may find a good rinse will keep it good, until the next clean.

you should rinse your "bio media". but do it in tank water. then replace it.

So I should change it once every few months perhaps, just as a general rule? I give it a bit of a rinse with every water change; it was pretty green today. Gave the bio media a rinse too, and the inside of the filter. Water seems a bit cloudy, though, so I'm wondering if I did something wrong...