HomeCompare fishRed rainbowfish vs Head-and-taillight tetra Red rainbowfish vs Head-and-taillight tetra: can they live together? Verdict: With cautionThe Red rainbowfish grows about twice as long as the Head-and-taillight tetra; watch for bullying or predation.Both are comfortable at 22–25°C (72–77°F).A pH of 7.0–8.0 suits both.Minimum tank for the pair: 150 L (40 US gal)Side by sideRed rainbowfishHead-and-taillight tetraAdult size12 cm (4.7 in)5 cm (2 in)Minimum tank150 L (40 US gal)75 L (20 US gal)Temperature22–25°C (72–77°F)22–26°C (72–79°F)pH7.0–8.06.0–8.0Hardness9–19 dGH (161–339 ppm)5–19 dGH (89–339 ppm)TemperamentPeacefulPeacefulCommunity tankGoodExcellentCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesRed rainbowfishGlossolepis incisusHead-and-taillight tetraHemigrammus ocellifer