Lol Soybean, i was going to point that out but didnt feel the need to get up and look if the washing up bowl was actually more than 8L or not.
I dont think its a bad thing to point out species that can live in 8L, there is still loads you can do, even without fish.
To be honest, a pair of sparkling gouramis would most likely be ok as would some of the species of Badis. Probably even room for one of the more unusual smaller species of fighter.
Lots of different species of shrimps and snails. I want one of the German Pink Ramshorns for my Spec. The Zebra Nerites look good too...
Just because you dont like Pico tanks, doesnt mean it isnt possible for others to come up with great little habitats.
There is a journal for a fluval spec in the right section which made me want to set up one and it looks great! worth a look!
For me its more the growing the moss in a cool way, the cherry shrimp keep the moss clean and make it grow better!