I have the same problem. The standard flow from the spray bar is too strong. My fish were always stressed and my plants were blowing around way too much. My temporary solution is to install the valve that came with it and restrict flow .
Others I know have enlarged the factory holes by drilling. This is probably better as you can attain more flow, but less powerful..
What I plan on doing is running a spray bar across the entire back bottom, maybe 2 inches up from substrat, aiming the nozzles about 45 deg up. I plan on having a valve to fine tune flow.
Any idea where I can get a couple of spray bars?