Maybe of interest ... http://www.trailerlife.com/output.cfm?id=859609

"Larry Bradley" wrote in message
...
Late getting into this - just got back form a summer on the boat. We
live on the boat all summer, and the holding tak gets a lot of use -
odor isn't too bad, but the 1st mate complains about it all the time.

The system is 34 years old. The tank is polyethylene, I think, and
appears to be in good shape. The hose from the head to the tank is
real heavy red hose, and it too looks to be in good shape. The tank is
behind the head - the hose run is about 3 feet, most of it vertical.
Since we have a relatively small tank (maybe 15 gallons), we put as
little water through as possible, so we can go for a week to 10 days
between pumpouts. However, this procedure leaves some liquid type
waste in the hose.

I've been using the traditional head chemicals, of the "kill
everything that moves" variety, and have just started heading about
this product "Odorloss". I gather it is one of the enzyme thingys. IfI
want to switch to this, what is the best way to get all the old
chemical out? Just flush, pump, flush, pump?

My tank vent setup is dumb - a right angle at the tank, then about a
six foot run of 5/8" hose forward, then a vent.

My head and tank is just forward of midships. I could run a vent hose
to a vent in the hull right there - about 1 foot of hose. I don't know
if there is any way to install a larger vent connection to the tank.
Would just shortening the hose help? Should the hull vent be one of
the kind with the small holes and the screen, or should I just use a
plastic through-hull? Should I make the vent connection a lot larger?
If so, any thoughts on how to fasten a larger hose connection the the
polyethylene tank?

How about the hose? What is the best hose to replace the old one with?

I want to keep the 1st mate happy, and a nice smelling boat helps.

Thanks

Jere Lull wrote:

In article ,
Peggie Hall wrote:

Any of the above is possible...the one thing I'm sure of is that the
problem IS the tank vent--that something about it has changed that's
reducing the air flow. Find it and you'll cure the odor problem.

I'm mostly tagging in to thank you for your advice. Backing up your
analysis isn't really needed.

This spring, I plumbed our second vent line a bit better. It's 3/4" ID,
a couple of feet long, and now goes pretty much straight up to a nylon
through-hull high on the hull. The first vent is about 1.25" ID and
only a few inches long, but includes a 90 degree bend. Not an ideal
installation, but the results of the combination are amazing. With just
the single actually active vent, we still had odor when we flushed. Now,
the tank contents are virtually odor free, as we found out when the
toilet backed up. The major smell was a slightly yeasty odor from what I
believe was an overdose of Odorloss (it diminished greatly the second
time a few weeks later), and there's nothing noticable downwind when
someone flushes.

Oxygen, LOTS of oxygen!

Larry Bradley VE3CRX
Remove "removeme" from my e-mail address for direct mail
Ottawa, Canada

(use the e-mail address above to send directly to me)