Q:

can capacitor increase flow/quantity of water in water pump

can capacitor increase flow/quantity of water in water pump. we are already using capacitor of 25 uf. can water quantity be increased if we use capacitor of 30 uf or any higher which u suggest.

A:

No, the wrong sized capacitor will make things worse.
The purpose of a run capacitor is to energise a second winding in the motor. It's capacitance is chosen to produce the correct phase difference between the windings. A smaller value will produce less torque. A higher value will overheat the motor.

simulate this circuit – Schematic created using CircuitLab
See 

Single-phase induction motors
Motor Capacitor FAQ

