I haven't noticed that chart you mention, would like to see that, if you could point me to it Simon?
On the compatibility, i wouldn't. Generally speaking, sedate fish like gourami, angels, Discus
, many of the medium cichlids, etc. do not go well with active fish. And active fish include the danio, barbs and some characins. Less active would be rasbora, some characins. There can be quite a difference.
To illustrate, I have a 90g river habitat now and I deliberately set it up for some of the more active fish. I have a group of Botia kubotai
loaches, Black Ruby Barb
, Congo Tetra
, Emperor Tetra
(not by design, these 12 are fry that are now mature) and Golden Pencilfish
. These are all active swimmers, and they do get along fine.
By contrast in the 115g I have much calmer fish, various characins including hatchetfish, Roberts Tetra
, Brilliant Rummynose Tetra, Pretty Tetra
, Spotted Headstander
, Whiptail Catfish
, Cardinal Tetra
and my 30+ corys. These fish swim, some more than others, but sitting in front of both tanks for a spell makes it very obvious that the two tanks are a world apart. I just can't imagine any of the fish in the 90g being in the 115g, it would simply drive the fish in their nuts.
On the Pearl Gourami
, depending upon tank size, one male and 2 or 3 females would be best. Males are territorial. Glowlight Tetra
should be OK except the Gourami might try to eat them if they are still small and the PG are mature. Same holds for any of the slender tetra (neon, etc). Rasbora do well with gourami, here the Harlequin Rasbora
, maybe Scissortail Rasbora
(gets large, 6"). The quieter tetra in the Rosy clade would work, just avoid the fin nippers.