Okay so my levels are fine (Ammo 0, Nitrites 0, Nitrates 40ppm ie on the high side of normal) and the other water parameters were well within the gourami's range (Ph 7, GH 75/soft, KH 90-120ppm, 76o f).
So before I got the Zebra Loach and the Dwarf Puffer (who are temporary additions to clean...