I blend at purée for jus a few moments for the medium grade. Always frozen. Then I put the stuff into ice trays and freeze hard. Then I chop into smaller bits kept in a tuppleware thing.

For my Lps I do the same thing only I blend until a goopy mess. Them I put that into a ziplock and smooth it out nice and thin and flat. Then I freeze. When I need to feed the coral I use the scientific method of "breaking off a chunk" thaw and feed.