When making a rocket with Alka Seltzer and water, why don't you crush up the Alka Seltzer tablet?

I recently did an experiment where I added half a tablet of Alka Seltzer to a film canister half filled with water to make a rocket. I found that when I crushed up the tablet, the rocket did not go as high. I was wondering why it worked better without crushing it.When making a rocket with Alka Seltzer and water, why don't you crush up the Alka Seltzer tablet?
faster and more powerful reaction in tablet form must eat away to center, when crushed all at once





more bang for the buck