Depends on what you want to do. They are both very effective at doing
different things. Kinda like asking 'Which is better, a sedan or a pickup
truck'. A bottom drain will keep the bottom clean if installed right. Won't
do a thing for crap in the water column, leaves, grass trimmings etc until
it settles to the bottom. A skimmer will remove most debris that falls into
the pond and will float for a period of time, again, if installed right. A
skimmer won't help with stuff that doesn't float on the surface For the best
of both worlds, use both.

Paul

"Drew Cutter" wrote in message
...
Which is more effective ?