Roger Long wrote:
The sink drain "T" into the head intake line works great although
it means a lot of head pumping.

What I meant by lots of head pumping was filling a 13 gallon holding
tank by pumping the head.

You--and most other boat owners too--need to learn to use the "dry" mode
to do more than pump the last of the water out of the bowl. Few people
realize that any manual toilet that's working anywhere near factory
specs can move bowl contents up to 6 linear feet (further if you get
some help from gravity, at least 4' vertically, in the dry mode. You can
cut your flush water by at least 50%, doubling the number of flushes
your tank can hold if you'll do this:

Pump only 2-3x in the wet mode to wet the bowl ahead of use...or add 2-3
cupfuls from the sink ahead of solids. Switch to dry. After use, pump
enough times in the dry mode to move the bowl contents to the
tank...then switch to wet only long enough to rinse the bowl...and back
to dry to push the rinse water through to the tank.

--
Peggie
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Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304