Mine never bothered the other fish. Not even the Bolivians or German Blue Rams. But I can't keep serpae's. Not sure if it's the water, but after a couple months, their skin starts getting a dried white look, and they die off. Same with my Bleeding Hearts. The Blue Flames seem to be doing ok though so far. It's happening in both my 29G as well as my 75G, as I had serpae's in both, and both suffered the same fate. So no more serpae's for me. My neons, cardinals, and rummies are all doing just fine, and my rasboras are over 2 1/2 years old, and doing great. Just some reason those more round-shaped tetras don't do well here. My tiger barbs in my 55G are doing great as well. They are nearing 2 3/4 inches.