HomeCompare fishLake Kutubu rainbowfish vs Slim betta Lake Kutubu rainbowfish vs Slim betta: can they live together? Verdict: With cautionThe Slim betta can be semi-aggressive or nip fins.Their temperature ranges only just meet, at 24°C (75°F).A pH of 7.0–7.5 suits both.Minimum tank for the pair: 210 L (55 US gal)Side by sideLake Kutubu rainbowfishSlim bettaAdult size10 cm (3.9 in)10 cm (3.9 in)Minimum tank210 L (55 US gal)75 L (20 US gal)Temperature20–24°C (68–75°F)24–30°C (75–86°F)pH7.0–8.06.5–7.5Hardness9–12 dGH (161–214 ppm)5–15 dGH (89–268 ppm)TemperamentPeacefulSemi-aggressiveCommunity tankGoodGoodCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesLake Kutubu rainbowfishMelanotaenia lacustrisSlim bettaBetta bellica