barb-e
Fish Crazy
I have a Tetra whisper 10 or 15 power filter in my ten gallon aquarium. It used a bio bag and this little black sponge thing. My tanks been set up for two months and I know i'll have to change the filter media eventually. I've heard that you shouldn't change everything at once because you will get rid of benificial bacteria. Well, what is everything? What is supposed to be changed and how often? What method is best? 
