Ballast pumps have individual suction filters provided. Onboard your ship it is seen that during ballasting the ballast pump suction is getting blocked very frequently during ballasting. You should:

A. Remove the suction filter because there is already sea suction filter to protect the pump
B. Clean the suction filters as frequently as required, but also open and inspect the sea chest filters
C. Stop using the pump and keep filling the tanks by gravity
D. Suspend the ballasting operation