Thanks to a li'l gizmo called the Uniseal
UNISEAL it's not that hard to relocate fittings on most tanks...seal the original fittings with a threaded plug and good wrap of Teflon tape.
Q:
if the macerator pump is below the tank level (as is ours), will it pump from a pick-up tube through the top like that? Or does the pump have to be above the tank? Or does it matter?
Macerator pumps are rated to lift at least 4', so it should have no problem pulling the waste out of any tank that isn't taller than that. But what if you left the original discharge fitting in place and dedicated it to the macerator pump and installed a new pumpout fitting on the top?
Q:
If using a single pump-out fitting and a T for both deck pump-out and macerator discharge... what's the downside of that T fitting?
I don't know that there always is one...there is when the only fitting is at the bottom of the tank because there's no way to shut off the flow of tank contents to the macerator if necessary--and we all know that macerators never need attention when the tank is empty. If you were to go with the pair of "high and low" discharge fittings, you could put a shutoff valve on the on the one dedicated to macerator.
Give me a shout via PM or email if you want to brainstorm the specifics of relocating your discharge and vent fittings in more detail than is practical here.