HomeCompare fishSlim betta vs Northern trout gudgeon Slim betta vs Northern trout gudgeon: can they live together? Verdict: With cautionThe Northern trout gudgeon can be semi-aggressive or nip fins.The Slim betta can be semi-aggressive or nip fins.Both are comfortable at 24–26°C (75–79°F).A pH of 6.5–7.5 suits both.Minimum tank for the pair: 150 L (40 US gal)Side by sideSlim bettaNorthern trout gudgeonAdult size10 cm (3.9 in)17.5 cm (6.9 in)Minimum tank75 L (20 US gal)150 L (40 US gal)Temperature24–30°C (75–86°F)24–26°C (75–79°F)pH6.5–7.56.0–7.8Hardness5–15 dGH (89–268 ppm)–TemperamentSemi-aggressiveSemi-aggressiveCommunity tankGoodGoodCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesSlim bettaBetta bellicaNorthern trout gudgeonMogurnda mogurnda