I have moved into a house with a partially built pond. It has a brick
above-gound structure, about 10'long x 5' wide, with a 2' deep
squarish hole in the ground. I am thinking about lining it with a EPDM
liner, but I don't want any fish. I may add a plant or two, but mostly
like the idea of looking at cool water on a hot day. I've been reading
library books and webpages, etc., but everything seems to be designed
for fish and plants. I'd like to know if I will need the whole
shebang: pump, filter, UV light, for what will essentially be a
reflecting pool. If I don't need it now, will I need it if I add a
plant or two? I might like to add a fountain later and know I need a
pump for that, but would I then also need a filter? Any help
appreciated for this new-to-the-pond world.

There's a (not very good) picture of the pond structure at
http://www.sonic.net/dana/pond/