Installing a total head system from scratch.
Adam, Might I suggest that you get hold of a West Marine Catalog and in the Plumbing & Ventilation section, you'll find the West Advisor pages (pale blue in color)? Take a look at what they call "Our Favorite Method" and study the routing of the plumbing in the illustration. Give thought to basing your installation in that. Now, given that you are in Montreal and that I haven't the foggiest idea what the overboard discharge laws are, you may or may not want to include a second through hull fitting on the discharge side. Actually, if it were me, I would install two through hull fittings anyway and if local regulations prohibited overboard discharge, I'd disable that seacock. I say that because I'd be thinking about the day I were to sell the boat and wouldn't want the lack of a seacock there to be a deal breaker, but that's crazy me. Anyhow, back to the illustration. I have installed a number of head systems exactly like their method with one major exception. I use a T-fitting where they show a Y-valve at #8. Stare at it for a few seconds and you'll see that the Y-valve doesn't really get you much. After all, if you cleanse the tank with clean water be it salt, brackish or fresh, the length of hose between the macerator and the seacock will only contain clean water anyhow. It's as simple as it can get that way and works just fine for overboard or on deck pump out discharge. Hint: If your laws are like USCG regulations here, the seacock has to be locked closed when not in use or at least made difficult to open. My solution has been to remove the stainless handle from the side of the seacock and attach it to a tether that ends up disappearing into the dry bilge. It's closed when not in use and totally disabled insofar as there is no handle attached to it. In order to open it one had has to consciously retrieve the handle and slip it onto the seacock to use it. That seemed to satisfy the Coast Guard when I clearly told them that was what I planned to do before my first installation. What they're after is something that makes you go well out of your way to open that seacock and apparently this qualifies. Hope this helps, Glyn Judson, E31 hull #55, Marina del REy, CA