Peggie, I have a question, kinda related to this thread. I think I've
read/understood that a well "aired" holding tank is the best way
to reduce oders.

Yep...oxygen is the key to odor elimination.

So, being an engineer, I'm wondering if a two
hose holding tank vent arrangement...one "inlet" and one "outlet",
might work.
The forward hose leads to the bow, the aft hose leads to the
stern.

It would actually work better if both lines went forward...'cuz that
would mean air would be forced into the tank no matter which tack you're
on. Nor does it require two vent lines if the vent line is short enough
( 5') and has a 1" ID...'cuz air forced in has no trouble pushing
gasses in the tank out the same line.

The theory is that there would be constant airflow into,
(and out of) the holding tank. assuming the vents at each end
encouraged such flow.

A line leading aft that's too long wouldn't be under enoug pressure to
get the job done without an inline exhaust fan to help it. You'd
actually be better off with a single 1" short vent.


Is this a stupid idea?

Noooo...not stupid at all! It only proves you're thinking in the right
direction. I'd have to see a diagragm of your installation before I
could tell you what you need to do to make it work.

--
Peggie
----------
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://www.seaworthy.com/html/get_ri...oat_odors.html