I actually heard a Walmart employee tell a customer that 2 male bettas can live together in a 10g w/ 3 oscars, a frog & several neon tetras & an angel fish! I stepped in real quick, and informed the customer about the poor judgement & lack of knowledge the employee displayed. That was total tank annihilation waiting 2 happen!!! The lady was so grateful for my advice. In the end she bought a blue CT and the 6 neon tetras, a 10g starter kit, water conditioner, ph kit, crushed shells (prettier than gravel I guess), aquarium salt, stress coat, a heater & decor (incl fake plants). She also bought a 2nd betta, but on her way out, handed the cup to my 2yr old son.... her way of thanking us, she said. The employee was so miffed, lol! It kills me how they put someone in the fish dept, that doesn't know the 1st thing about aquariums, or which fish are even compatible! I made sure the store manager was aware he had an flaming idiot working in pets.... Ugh!!!