Help with new glofish tetras

[Rangerbob86]

I just got three new glofish tetras. They are the only fish in my new (cycled) 20 gallon tank. Everything seemed fine on day one, but now after two days, I have some concerns. One of them barely swims around, won't eat, and has a white lump on its side. I'm worried he won't make it much longer. The other two are very active, but one constantly chases the other into the same corner and when he tries to swim out, he gets chased back in and nipped at. Do I need to do anything at this point? I wasn't sure if three would be enough but I didn't want to overload my new tank right off the bat. Any help would be appreciated!

Water conditions seem fine...No ammonia or nitrite and minimal nitrate. 78 degrees Fahrenheit, 8 gh, 3 kh, 7.4 ph.

Also, when I referred to a fish as "he" above, I really have no idea what sex any of them are...

 

[FWFishTanks]

I had the same lump problem with a harlequin rasbora. What I did was increase the water temperature to about 78-80 degrees Fahrenheit and add some medicine made to cure fungal infections. I did this and the lump slowly dwindled to a speck, and then the lump was gone. This fish was healthy again, and is still alive now. As for the aggression issues, maybe take the aggressive tetra out, add 3 , more tetras, let them get adjusted, and then add the aggressive one back in. This may make him calmer. Good luck with your glofish!