Thanks, lisals. The dojo is between 6-8 inches long. It is hard to estimate length, but he or she is large. My favourite swords are the ozelot, both the red and green versions. You have gorgeous sword plants. I am going to step up my root tab fertilizing!
Good news about the ammonia reading. I hope your betta's eyes return to normal soon.
Do you dose potassium in your betta tank? Often those holes are a potassium deficiency. It will take a while to see an improvement, because it will be the new leaves that look better.