We have now sorted out our tank and my neon tetras are hiding away alot, i have 4 mollys 7 tiger barbs and 7 tetras also a red tailed shark and 3 bristle plecs. we did have 10 tetras but they seem to be dropping off. i want to rehouse my neon tetras but would like to replace them with a more hardy fish as the tigers seem to be bullys. does anyone have any tips on what i could add o my tank 3ft by 1ft by 1.5ft approx 20 galon/85 litres