The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
I'm not exactly sure how fast it is, not unrealistic, I got the set up second hand and the pump doesn't say the rate. I can break the flow with a bit of T PVC or similar if I wanted.
But I was just interested in a broad spectrum of fish that prefer fast flow.
The best way I can explain it is - I can drop some fine sand like gravel in the tank in a bit not directly in the flow of the pump (which is running diagonally across from far top right to bottom left corner) and it doesn't deviate, but in front of the flow, it moves a good 10 inches off its path.