He's definitely biting his tail (and perhaps other fins). I got home from work yesterday and his tail tip was sheared off neatly, straight across just like he got a hair cut. No sign of the piece of his tail in the tank so I assume he ate it?? (do they do this?)
I guess he will just be a high maintenance tail biter. I did a 100% water change last night and plan on changing out 50% on Monday (my usual water change schedule).
Otherwise he seems perfectly fine... so I guess just keeping clean water and changing up his environment once in awhile to reduce boredom may be best for now?