Congrats, I have had a deck pond going for 6 years now. I have even
kept it running through 3 cold midwestern winters with the help of a
little heater. I now drain it and use my main pond as my fish friends
winter retreat. I have had excellent luck with my deck pond and I use
no chemicals to control algae. I keep a couple of small fish and some
plants along with my small bottom filter. My pond gets quite a bit of
sun and I do have to add water quite frequently to make up for
evaporation & keep the temperature down below hot tub temps, but over
all my water stays very clear with a small amount of algae on the
sides/bottom of the pond. Best of luck.

FYI... racoons do love deck/patio ponds... I lost my favorite
shubunkins a couple of years ago. Now I have some nice big rocks with
hiding places for the fish to hide. Hopefully the racoons aren't at
the gym training.

http://members.cox.net/bokowski/deckpond.html