Okay, I'm tending to agree with the idea of 20l being too much for me, at least my first year in a dorm, as I'll be coming home for all the breaks and for the long breaks bringing it back with me. (I'll probably upgrade to a 20l when I get my off-campus apartment next fall.)
So, low light plants, moss, shrimps. Got it.
If i wanted to add a couple fish or other invertebrates, what would be the easiest choices? I'm not talking like huge numbers of fish or anything.