Six Banded Barb (Desmopuntius Hexazona)

Six dark bars flicker through tannin-stained forest streams.

The Six Banded Barb (Desmopuntius hexazona) is a peaceful, active schooling barb for soft, acidic blackwater community tanks with plants and tannins.

• Water conditions: The Six Banded Barb (Desmopuntius hexazona), still often sold as Puntius hexazona, is best kept in soft, acidic, blackwater-style water. Aim for a temperature of around 23–27°C, pH 5.5–7.0, and general hardness of roughly 1–10 dGH, with low carbonate hardness where possible. Ammonia and nitrite must read zero, and nitrate should be kept low, ideally below 20 ppm, through stocking sensibly and regular partial water changes. These barbs appreciate gentle to moderate flow, good oxygenation and stable parameters more than any single “perfect” number. If your tap water is hard or alkaline, mix it with RO water or use botanicals and leaf litter to soften and tint the water naturally, but make changes gradually. A tank of at least 80 cm / 20 US gallons is a practical minimum for a small group, while 90 cm or longer is better for active swimming. Keep the water clean, mature and well filtered without blasting the fish with strong current.
• Suitable tank mates: This is a peaceful schooling species that does best with other calm, soft-water community fish of similar size. Good companions include smaller rasboras such as harlequin, lambchop, chili and espei rasboras, plus ember tetras, cardinal tetras and other peaceful characins that tolerate soft, acidic conditions. Bottom dwellers such as Corydoras catfish, Otocinclus and kuhli loaches can work well in a mature setup, and adult cherry shrimp or snails are usually ignored, although very small shrimplets may be eaten. Avoid large, boisterous or aggressive tank mates, fin-nipping species, big cichlids, goldfish and livebearers that prefer hard, alkaline water. Tiger barbs and similar robust barbs are not ideal because their activity and nipping behaviour can stress the Six Banded Barb. Always quarantine new arrivals and observe group dynamics; if a tank mate becomes aggressive, remove it rather than allowing the school to be constantly harassed.
• Feeding habits: The Six Banded Barb is an omnivorous micro-predator that naturally picks at insects, crustaceans, algae and biofilm. In the aquarium, offer a varied diet of small foods rather than large flakes or pellets. A quality micro pellet or finely crushed flake can form the staple, supplemented with frozen or live daphnia, cyclops, brine shrimp, bloodworm, mosquito larvae and baby brineshrimp. Some vegetable matter is useful too, such as spirulina-rich foods, blanched spinach or a small amount of algae-based food. Feed two or three small meals a day, giving only what the group can clear within a minute or two, and avoid overfeeding because uneaten food quickly fouls soft-water tanks. Vary the diet regularly to support colour, condition and natural foraging behaviour. If the fish are shy at first, feed near the shoal and in smaller amounts until they settle.
• Care requirements: Keep Six Banded Barbs in a shoal of at least eight to ten, with twelve or more being preferable, as single specimens can become nervous and withdrawn. The ideal setup uses a dark substrate, dense planting, floating plants, driftwood, leaf litter and botanicals to create shade, cover and a natural blackwater feel. Dim lighting suits them well, and open swimming space should be provided alongside planted areas. Use a mature filter with gentle flow, maintain stable temperature and pH, and carry out weekly partial water changes of around 20–30%. They are small fish, typically reaching around 5 cm, so avoid oversized or boisterous tank mates. Acclimatise carefully by drip method, especially if the pH or hardness differs from the supplier’s water, and keep a tight-fitting lid because active barbs can jump. Observe for fin damage, lethargy or loss of colour, and act quickly if parameters drift. With consistent care, a well-maintained soft-water aquarium and a secure group, the Six Banded Barb makes a lively, understated centrepiece for the peaceful blackwater community.