if you raise the outer edges of the pvc with rocks,
or other things, the water will run to the center.
just put a funnel under the pvc so that the water will flow easily
into the bucket.
make small holes with a drill in the center of the pvc.
5 will do. you might have to put larger rocks or whatever under your
live plants because of the weight.
if you have any other spec questions just ask them.