New Small Pond.......Need Info Please

I have a very small back yard with a garden and decided to put a small
pond in with a waterfall. I did'nt plan on putting any fish in the
pond so I only made the pond 5' long by 2' wide by 1' deep. Just big
enough to add something nice to the existing garden. I planned on
putting in a few water plants. I have a few questions as this is the
first time I've ever had a pond and I don't know much about them. Are
there any chemicals I will need to put in the pond? How long should I
wait before I put any water plants in the pond? I filled it with
regular tap water. I used a pond caluculator and found my pond is
about 75 gallon. I'm just finding out now that I may have gone too
small with the pond because I'm hearing that I will have problems with
algae in small shallow ponds. Any Info you can give me on caring for a
small pond this size will be helpfull. By the way.....the pond is in
an area that gets sun most of the day.

Thanks in advance,
Mike