If you are going to put in a filter, you might as well cycle it.. use aged media from the other tank and it will be cycled almost instantly. But it's not essential if you are going to do the frequent water changes in a small container.
Ideally, I don't disagree with Scottyhorse.. though I think debating the size of tank issue is kind of pointless, too many people are going to do what they are going to do, regardless of the fish. I'm not suggesting the OP is doing this, clearly not the case !
If you can provide them, I think larger tanks are better, though as a baby it's not as much of an issue now as it will be once it is grown. Females can be larger than males, so it might grow a fair bit.
I used 2.5s because it was what I had room for and I ended up with two damaged fish whose owners wanted someone else to care for them.. so I took them on. I'd have preferred bigger tanks for them, but they did well enough in the 2.5s. Bare bottom, a bit of moss, small cycled filter without much flow, salt and almond leaves to help heal badly damaged fins.