the broucher does explain your solution already
Instructions:
Water flow decreases when the Venturi feature is used. If no air is desired or if you prefer to use the Maxi-Jet with the Prefilter Grid, do not install the Air Tube. Cover the Venturi opening with the enclosed clear-plastic Venturi Plug.
did you try it also without pluging the ventury opening so that it sucks water instead of air? and if you did what was the result?
as for the price of the pump all efforts to reduce the flow rate electricaly are probably more expencive than looking for a new and somewhat smaller version
Robert-Jan
Instructions:
Water flow decreases when the Venturi feature is used. If no air is desired or if you prefer to use the Maxi-Jet with the Prefilter Grid, do not install the Air Tube. Cover the Venturi opening with the enclosed clear-plastic Venturi Plug.
did you try it also without pluging the ventury opening so that it sucks water instead of air? and if you did what was the result?
as for the price of the pump all efforts to reduce the flow rate electricaly are probably more expencive than looking for a new and somewhat smaller version
Robert-Jan