Please Help with breaking the ice !!!

Hello community.

I know this is not a forun for this, but I figure some of you might have experienced this before, so I will give this a try.
I am doing a shot of breaking an ice ground, and I meet some problems.

1./ As you can see in the attachment, before the ball hit the ground, the ice is already broken, this is due to transparency of the material, of which I can't change.
Is there anyway to prevent that to happen? (What I am trying to get away now is to render another one with the ground unbroken, then do post) - but this is a preview render, which is only 1 min each frame. But I won't be able to do that when the shot is approved (more than 2h per frame...)

2./ I want to have a finer breaks (smaller pieces) but I dont want to go back and re calculate all of them all over again. Also, it takes tons of times to just break them smaller. Is there another quick way to do that rather than break them into 10 million pieces then recalculate?

I appriciate very much your help, and I wish you well.

Thank you