On Sat, 15 Jan 2005 03:51:01 GMT, Marc Levenson
wrote:

I drill it below the water line to avoid creating
microbubbles at the return outlets.

I've not experienced that. I get flow out of the hole. Nothing goes
in.

When I had the hole under the water line it kept getting clogged with
green stuff.

You can't beat the ripple on the surface, especially if you have
halides!!




kryppy wrote:

If it is coming down the return line you can drill a small hole in it
above the water line to break the syphon. Makes a nice ripple on top
as well. The stupid check valves will always fail at some point. The
hole can get clogged as well if it is not big enough.