Drop the spray bar down along the back right at the gravel level, angel the outflow so that is goes slightly up.
Also, have some decent surface current as well.

If you want to really amp things, add a CO2 disc below the current where is just starts to spread out in the surface flow in addition to the spray bar.

If plants have issues, then light/over growth etc are more likely the reason, of perhaps you may need lower KH's with specific species.

Regards,
Tom Barr