The Chocolate Gourami is known from blackwater rainforest peat swamps. Here the water is acidic, has negligible hardness, and is tannin stained from decaying plant matter. The aquarium must be biologically mature before this delicate species is added. Provide them with a myriad of hiding places amongst tangles of bogwood, rocky caves, and dense planting, including floating species to help diffuse the light. A dark coloured substrate and background will also help the fish to feel more confident and will bring out their best colours. Filtration should be efficient but water movement gentle, and we'd suggest the use of aquarium botanicals to help emulate the natural water conditions. The addition of leaf litter would further help in this respect - dried Indian Almond leaves (Terminalia catappa) are ideal and are readily available. Much attention must be paid to water quality since Chocolate Gouramis will not tolerate elevated nitrates or swings in water chemistry; small partial water changes should be carried out on a frequent basis. These fish are best maintained in small groups of 6 or more to dissipate their territorial aggression and a large aquarium will provide room to avoid conflict. If tankmates are desired, they should be small, peaceful, and thrive under soft, acidic conditions. Good companions could include shoals of small cyprinids such as Boraras spp. Eirmotus octozona, Kuhli loaches (Pangio spp.), Sundadanio spp., or Trigonostigma spp. Acclimatise very carefully.