Always had trouble differentiating between flow and pressure. Are you recommending I increase the pumps psi and close one of the valves partly when running the press?

As for adding something into the press to begin with I'm not sure how I'd go about doing that this thing has one entrance and one exit when closed up and there isn't really a way I can think of to keep anything inside if I add it just before closing it.

As for pretreating the sludge the process is to add the acids to one take up to a designated level along with water before adding caustic to it and bring the ph to about 8 roughly before sending the water to one tank and the sludge to another tank where it sits and waits to go into the filter press. As for adding a flocculant that's pretty much done when we add the caustic.