Hi Ingrid, I need your help!

I love your outdoor pond on your website, and I am planning on
building one either this fall or ealry next spring very close to
yours. I have a few questions, what type of plants should be used for
a veggie filter? Should filter pads be placed at the point of water
entry on the veggie filter? I estimated my pond to be about 300
gallons in size. 6'x3'x'3'. It will be placed on a concrete slab and
have about 6 solid hours of sunlight each day. The pond will be home
to exotic goldfish: ranchu, ryukins, and lionheads are what I have.

Thanks,
Ed