Mine is about 6" now.
They eat the same as my bichirs, carnivore pellets, left over feeders, shrimp. I also added quite a bit of vegetable based prepared foods that they seem to relish.
The love a good hiding spot and when put on light gravel the turn brown with black dots.
When placed on black or very dark gravel they turn so dark you can barely see their spots. I found with mine only started getting really nice feathers at about 4".
If your tank is not bigger than 90gal I would not put more than one unles you have ample hiding spots. They hate members of the same species. two of mine fought in a 300 gal but it was bare bottom.