I have an XP3 and Im will be cleaning it with next weeks water change. Do I just rinse out the foam inserts? And will that affect any BB in it? (I also have an AC300 HOB) for backup.
Depends what media you have in it. If your using the foam for just mechanical filtration then yes rinse them until clean with hot tap water. If you are using them for biological filtration also then you will need to rinse out in tank water. The chlorine will kill beneficial bacteria.