I have a juvenile frontosa in what was my 125g dempsey breeding tank and my ghost knife just chills in a corner of lava rock 24/7.... Ive rearanged the tank and mostly the lava rock to at least make him a formidable cave that he doesnt have live in secret. But... He likes the smallest of cracks. What would you recomend?? He isnt threatend by the frontosa. In fact i dont think that the frontosa even knows that there is another fish ib the tank.