So, I have a 55 gallon tank with some coral frags, red bubble tip anemone, 1 clown, 1 diamond back goby, 2 hermit crabs, 1 nassaris snail, and 2 pajama cardinals. I really need a larger fish as it looks pretty empty. I LOVE the Picasso triggerfish, but am worried about its aggressive nature. I also really like the pearlscale butterfly fish and the Valenti puffer. Any advice?