I have a 10gal with shrimp only. It has 2 whisper HOB's on it each rated for a 10gal tank. With the flow restricted shrimp seem fine. With the flow full blast they seem to move alot more. It seems them like the higher flow better. I am sure there are getting more O2, but I wonder if in the wild they are from high currents. Any ideas? They are Tigers and RCS.