Great tank FG. I have a 90p that is a little over two months old, and I'm fighting with the brown diatom on my HC just like you were. Seems you completely eradicated it from this last pic. What was the secret in the end? Trimming? Ferts? Patience? Every day I'm praying for the green lushness I see your pic, and the green that my glosso has no problem showing.
Also, I almost pulled the trigger on some chili rasoboras many times, but ended up going with some green rasboras and galaxy rasboras instead in the end. Beautiful fish you have. I have 9 ottos and 3 zebra ottos as well.
For anyone considering, I highly recommend the zebra ottos. Magnificent creatures. They are slightly larger then the normal otto, and they don't work as hard either, but they are terrific to watch.
Love your little nano! I have a mini-M that I just planted two weeks ago. Hoping it comes out almost as nice as yours.