It depends on what youre keeping. There are tons of freshwater forums dedicated to one type of fish, such as catfish, discus, apostogramma, certain african cichlids, and even stuff like planted tanks. Just type in a kind of fish and "forum" into google and you should find a few. Not all will have as high traffic volume as mfk, but you can easily check by finding the "most recent postings" filter to see how active they are. Personally, I dont really go on many other forums unless I have a specialty question, but mfk usually is a pretty good catch-all.