Even if you can't get all of it off, try to lower the thickness of the snow so that more cold air can get to the slush.
As I always say, you need three things to make a rink: water, cold and a pile of patience. You are about to be tested on #3. :-)
Making Backyard Rinks from 1999-2015
Twitter: @kevmac_5 or @macisaac_odr
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