12 angelfish in 473 litre (12

I bought 12 assorted Angelfish (koi, veil marble, gold/white, striped red eye?) about 4 months ago in hopes of having 3 pairs, maybe keeping 4-8. I planned to take the misfits back to my lfs. I should have done a lot more reading before buying this many. They are pretty large now (3 inches not...