Yep! you can change them in your control panel settings ~
There had also been a problem when users use bother bettafish.com and Tropicalfishkeeping.com. The issue happens when you subscribe to a new post on bettafish, you get UN subscribed from all your posts on Tropical Fish Keeping. Let me know if that's what you're observing!
And one more very useful little tool to subscribe to a thread you are interested in following, but do not necessarily want to make a post in, is the subscribe button.
Above the post at the top right side is a drop down menu which says "thread tools".
If you click on that, you should see an option which lets you subscribe to thethread you are viewing
forum community dedicated to tropical fish owners and enthusiasts. Come join the discussion about species,breeding, health, behavior, aquariums, adopting, care, classifieds, and more! Open to fish, plants and reptiles living in freshwater or saltwater environments.