Thank you!
WE had tried danio kyathits (which we have an over abundance of -- anyone want some?), and they hide in the rocks at the bottom

We do have a log in the middle but not enough eddy. I wonder if giant danios might like it more, but they are big fish for a 55 g
We had a couple Vietnamese White Clouds in the big tank (remainders of a larger school) and put them in, and they seem to not even
notice the current! Fortunately, we already had a small school of them on order from WetSpot, and they arrived yesterday and are in a q-tank. Hopefully in a month or so we will have a bit of a school (may try breeding them after quarantine and before addding them to the river tank, though)