Pump what ? Ask him to use his d..ck to pump lah.

Water leakage is a headache problem. Have to fix the source ,as water will always find a way to get to you no matter how you block it.

Don't know what pump.  A kind of liquid that can stop the leakage.  Not sure how it works etc.  But he guarantees that the problem will be solved- of course his guarantee has no value.

Pool in the ground is okay as any minor leakage is acceptable, nobody will notice. Also,if the ground water table is low, it will not have much pressure to squeeze into any minor defects.

Whereas for our bro problem, gravity is always there. Water will find you no matter what you pump.

Water can only goes down, never up lah.