I have a 1200 gallon pond in Miami Beach. I'm 1/2 block from the bay
and 3 blocks from the ocean with two canals in between. So one would
think that we're protected from much cold. Temps went into high 40's last
week for maybe two days. These lows were not long lived for these two
days as well. The sun still shines here, its only the breeze that gives you
a chill.

The point:
Since this cold front our fish are all cowered in one corner together. They
don't
seem to want to move more than 2'. Any ideas? I don't see any signs of
critters.