Replacing/cleaning HOB filter

[Finecheapwine4u]

I I've done some research but couldn't find anything solid. I have a 20g reef with a emperor 280 filter along with a 240gph powerhead. How often do you change your filter. It says to do so once a month. Do y'all just wash it to keep bacteria or replace entirely.
Thanks!

 

[Daniel Fishy]

The blue floss you can replace, the extra one for chemical you can replace the charcoal. Kind of depends on how dirty tank is and feeding I do mine once a month also. Never wash bio wheel or let it dry out just put it in tank to keep it wet. You can swish wheel around in tank water if it's really full of build on outside.