Hallo Stefanie, nice to hear from you! 🙂
Yes, I think the same as you, I’ve in all my tanks shrimps, they clean, they give some live food.
In my Paro tank there were many seaweed (Algen) when I came back from holidays and I found two dead shrimps floated in the front of the tank.. Many of my swimming plants had died, perhaps because I unfortunately left the top on the tank…. Perhaps the shrimps didn’t like the rotten mud of the plants?
Or they weren’t bred in black water but in normal tap water….