HomeCompare fishRed rainbowfish vs Black ghost Red rainbowfish vs Black ghost: can they live together? Verdict: Not recommendedThe Black ghost is aggressive towards other fish.An adult Black ghost is about 4 times the length of a Red rainbowfish and may eat it.Both are comfortable at 23–25°C (73–77°F).A pH of 7.0–8.0 suits both.Side by sideRed rainbowfishBlack ghostAdult size12 cm (4.7 in)50 cm (20 in)Minimum tank150 L (40 US gal)210 L (55 US gal)Temperature22–25°C (72–77°F)23–28°C (73–82°F)pH7.0–8.06.0–8.0Hardness9–19 dGH (161–339 ppm)5–10 dGH (89–178 ppm)TemperamentPeacefulAggressiveCommunity tankGoodGoodCare levelEasyModerateDietOmnivoreOmnivoreSpecies profilesRed rainbowfishGlossolepis incisusBlack ghostApteronotus albifrons