How do I reply to a comment on fluther?

I think you can click on their name and reply to them with a personal message. Not too sure though.
Hope this works for you :-)

If you are logged in to that Fluther press reply, if you’re browsing the public comments on some random users page and want to reply to that you’ll have to do it manually.

to markyy: There is no reply button or link, even on a fluther we started. It’s a “Thank [so-and-so]” link that takes you to their page.

I browsed the “replies” topic, and it seems if you use an @ symbol before someone’s name, it gives a drop down with names, then you click them to insert them… that makes it a reply, from what I gathered. For example, @Sandydog @markyy

Oh, you mean in a question. I misunderstood, and thought you were talking about leaving a public/private comment on another user’s account (for example, Master0fPuppets comments).

Kudos for finding the answer, using the @ feature on fluther to respond always seems hard to figure out for new users. There’s more cool stuff explained in the FAQ

I don’t know but I’d find out before I did it. I just made a comment that was off topic but related to a comment someone else posted and I have had the pleasure of a gang bang for my faux pas. I am reading the site guidelines but haven’t come across anything specific regarding this issue yet. I’ll let you know what I find. Tread lightly, some of these people carry big sticks. lol