If your water is hard, you can get away without any salt for Orange Chromides, in India and Sri Lanka, they live in either brackish and fresh, but if your water is soft lacking in minerals, it might be a stretch.
The line bred versions (like the predominantly orange ones in the Bluegrass list) are adapted thru years of aquarium conditioning to common aquarium conditions, I first saw line bred versions way back in the 1950s.
I have also kept Etroplus suratensis, and although they are said to be brackish, mine did well into totally fresh (albeit a hardness of 250 ppm) and even spawned.

These however, get the size of dinner plates, so too large for your tank.
Below spawning in fresh.

These are also primarily vegetarian, and I would feed everything from romaine lettuce to dandelions from the yard.

Some of my favorite cichlids, they have one of the most primitive hearing organs, that are only shared by their Madagascan cousins, the Paretroplus.
Below Paretroplus maculatus

These are snail eaters, and use their can opener like teeth to extract snail flesh (they also get quite large)