You have the ability to change how you want the posts in a thread rolled out. You can have the newest first, or the oldest first. Most forums on the interest always have the oldest first and as you scroll down each post is a newer one. You can customize Tidal Fish to suit your taste.
Go to the "My Account" link which is at the top of all pages on Tidal Fish.

Once in My Account, go to 'Edit Options"
under "Settings and Options" scroll down to "Thread Display Options"
under "Thread Display Mode" select how you want your view to be
Scroll all the way to the bottom of the page and hit "Save Changes"
You are all set.