Originally Posted by Ruben
If you are talking about font size that would be done with the style editor. To many areas to list to change.
If you are talking about the text area.
One place to start would be for posts and replys
Control Panel ยป Display Options+Post/Reply Page Options
Tweak the
Default Textarea Columns:
Default Textarea Rows:

The user has a option when posting to make the text area taller while posting. It is the double arrows in the post toolbar


thanks bro