After some switching around, I was able to move the E. humboldtii Knife and the Zebra Knife together into a 40g (With some others) It all seems to be going well.
I hadn't seen the Zebra Knife in awhile (Always would hide until night) so I got a bit worried, and moved some of the rocks around and was able to get a pic of him. He has grown maybe 1/2 an inch.
Pics
you got some really nice lookin knives there... i dont have any, but i will be getting an ABK soon! i like your BGK the best. BGK's are definitely my fav aquarium fish lol.