On Thu, 22 Mar 2007 22:48:39 GMT, "Gordon Wedman"
wrote:

This is how I plan to run my hoses:
-toilet to Y-valve
-Y-valve outlets directly to tank and to thru hull via vented loop
-line from second tank pickup to macerator
-macerator discharge into T which is in the line between the Y-valve and
vented loop

When you use the macerator the Y-valve will prevent backflow into the
toilet.

My old boat was like that and it worked fine. The macerator pump was
used to empty the holding tank when off shore.