Betta Fish: Some opinions on my Tank and Girls?

Those are my 4 girls that live together in my Tank. I have closely observed them and still keep observing them. I have Never seen aggressiv behavior and dis a few tricks to make it work.
One of them got some genetical issues (the Blue and Black one) where she has a crooked spine. I first saw it as i got home from the pet Store.

Please feel free to give your opinion on the tank, the Fish and the fact that I keep them together.