HomeCompare fishHead-and-taillight tetra vs Flag tetra Head-and-taillight tetra vs Flag tetra: can they live together? Verdict: CompatibleBoth are comfortable at 22–26°C (72–79°F).A pH of 6.0–7.5 suits both.Minimum tank for the pair: 75 L (20 US gal)Side by sideHead-and-taillight tetraFlag tetraAdult size5 cm (2 in)3.4 cm (1.3 in)Minimum tank75 L (20 US gal)55 L (15 US gal)Temperature22–26°C (72–79°F)22–28°C (72–82°F)pH6.0–8.05.5–7.5Hardness5–19 dGH (89–339 ppm)5–15 dGH (89–268 ppm)TemperamentPeacefulPeacefulCommunity tankExcellentGoodCare levelEasyModerateDietOmnivoreOmnivoreSpecies profilesHead-and-taillight tetraHemigrammus ocelliferFlag tetraHyphessobrycon heterorhabdus