HomeCompare fishBlackline rasbora vs Arulius barb Blackline rasbora vs Arulius barb: can they live together? Verdict: With cautionThe Arulius barb grows about twice as long as the Blackline rasbora; watch for bullying or predation.Both are comfortable at 22–25°C (72–77°F).A pH of 6.5–7.0 suits both.Minimum tank for the pair: 210 L (55 US gal)Side by sideBlackline rasboraArulius barbAdult size5 cm (2 in)12 cm (4.7 in)Minimum tank115 L (30 US gal)210 L (55 US gal)Temperature22–26°C (72–79°F)19–25°C (66–77°F)pH6.5–7.06.0–8.0Hardness5–12 dGH (89–214 ppm)2–10 dGH (36–178 ppm)TemperamentPeacefulPeacefulCommunity tankExcellentGoodCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesBlackline rasboraRasbora borapetensisArulius barbPuntius arulius