I noticed something about my gudgeons. A lot of places say that peacock gudgeons don't like high flow a lot but out of curiosity I did speed the flow up to max to see what they'd do. The max setting isn't a lot but it still produces a fair amount of flow.
My male came out of hiding in his male cave and went directly into the stream. He stayed in the stream and was actually playing in it. Then Betsy tried it a little and seemed to enjoy it.
Captain Nemo also went up directly to the output section and was trying it.
They could have hid from the flow of water and got all stressed but no their loving the flow and the speed boost they get when they go with it as well. It's like their version of a slide...