I am adding fish to my newly bought 55 gallon tank. I have 6 serpae tetras, 3 corydoaras, 1 blue gourami, and 1 flame gourami. My serpae tetras are picking on my goramis.(No surprise there) I plan to add 9 more serpae tetras to my tank to make it around 15. Will this help the nipping? If not should I return my serpae for another tetra? I really don't want to do that. Please help. Thanks