Any Problem With Changing Filter Insert?

Hey everyone... I have a Hang on Back filter good for up to 20 gallons on my 16 gallon freshwater tank.. It has done great for the past 9 months which it has been running..
But I just noticed today as I did my water change that the filter seems to be plugged becuase there is water coming out the inlet section more then the outlet... I do rinse my finter once ever 2 weeks in treated water but it doesnt seem to help..
I have a heavily planted tank so would it affect my biological filter if I change the filter insert.. as there should be plenty of bacteria on the plants and in the gravel.. or is there a procedure I should follow before I change it
Thanks a lot!

 

Yes, it will affect your bacteria colonies (yes, there's some on the surfaces in the tank, but the vast majority is in the media). What kind of filter & cartridge is it?

Is there any way you can fit a coarse sponge in the filter with the existing cartridge? If you can do that, you can run the filter with both for a couple weeks then get rid of the cartridge. With the coarse spong, you can clean it out a little more thoroughly and it will last a lot longer. Then, once you get rid of the cartridge, you can add a second coarse sponge and if you ever do have to replace one, you'll still have a backup in there so you won't loose all your bacteria.

-Chelle