Peggie Hall has just joined our Message Board. Randy, why not post a question there. My guess is that her first answer will be check your bilge, but I'm sure yours is spotless.

Give her a try on co.com, too, here: [url]http://forums.catalina.sailboatowners.com/forumdisplay.php?f=31[/url]

And there's this "Primer" --- [url]http://c34.org/bbs/index.php/topic,5755.0.html[/url]

This may sound bogus, but when I get a bit of holding tank odor, I get out my trusty bottle of Tilex and spray the holding tank, the area around it and the hoses. The smell goes away. I know this doesn't make any sense, but it works for me, year after year. My hoses are original, I don't have any leaks in the tank, so I don't really know where the odor originates. I only get a noticeable odor once or twice a year, so replacing the hoses hasn't been a priority yet.

I have noticed an odor, from tiime to time. I have a Sealand/dometic vacuflush, new pipes, etc.

I have determined odor comes from vent pipe in stanchion. When starboard bulkhead window is open, odor migrates into salon...

Al

Just for the heck of it check to make sure your batteries aren't being over charged. One of my old dock mates had an egg water smell in his boat and we found it was his batteries cooking

I had the same problem - constant low grade odor and stronger odor when somebody flushed the (vacu pump) toilet. I forget where I saw it, but I got the following suggested treatment: Pump out the holding tank and refill with fresh water. Repeat this process several times. Then pour a couple of gallons of white vinegar in the holding tank and fill once again with fresh water. (What I added to this was to flush a water vinegar solution down the toilet several times to let it sit in the hoses.) Take your boat out sailing for at least a few hours to allow the water & vinegar to slosh around. Then let it sit for several days and once again pump out. Fill with fresh water but first put a couple of boxes of baking soda in the tank (also through the toilet). Then pump this out.

I did this and the odor is gone. I don't know if it will return, but it worked for now anyway.

John,

I think the term for the procedure you performed would be Douche.
Bet your boat smells fresh as daisy after.

Randy, as I recall you are in fresh water, that in itself should minimize the head oder. I have not Douched my system and that sounds like a good plan but, just switching from salt to fresh water made a huge difference on my boat. I do not know if there are enough micro organisms in your local water to effect the odor. In salt water once those oganisms die from lack of oxygen in the head and holding tank it really gets foul.

John and Randy,
I have a similar problem with a low-grade smell around the tank, but cannot see any problems. Also, my external tank monitor would never read less than 46%, even thought the tank had just been pumped out. I figured there was a bunch of "stuff" stuck in there. A few weeks ago I read about the "GEO Method" (google it to get the details). Last weekend I pumped out the tank, put in 2 cups of Calgon water softener, 2 cups of detergent, then filled it 2/3 full with fresh water thru the pumpout fitting. It's been sitting all week. I plan to go sailing this weekend to slosh it around, and then pump it out. I'll report back how it works. Further reading has told me that the second half of the GEO Method, large doses of bleach, is not something you should do, so I will just see how the water softener and detergent works. Fingers crossed.....

Last year I elected to take the vent fitting off the top of my supposedly empty holding tank, then used a long steel rod (slightly curved) to poke aound. I found surprisingly little solid matter in there.

It may not be the best method, but I was told to add a cup or so of original formula Pine-Sol to the tank with some water and let it slosh a while underway. When it gets pumped out later, the hope is that is has broken up any solid deposits that might otherwise remain. We have no reason to doubt its effectiveness, but can't prove it one way or another except for the inspection noted above.

[QUOTE=alpace;6270]I have noticed an odor, from tiime to time. I have a Sealand/dometic vacuflush, new pipes, etc.

I have determined odor comes from vent pipe in stanchion. When starboard bulkhead window is open, odor migrates into salon...

Al[/QUOTE]

Al, Peggie recommends Odorless from Raritan. See my link above.

Duane, Peggie also recommends PureAyre for odors outside the tank, not tilex.

by the way, I forgot to mention with that "douche" treatment I described on this thread: Leave the water and baking soda mix in the holding tank for a few days before pumping out.

John,

When I first read your douche treatment plan, it made me recall the bath tube toy boats that came in cereal boxes in the 50's. You would put a drop of viniger in a chamber with some baking soda and snap it closed as I recall. The boat would then propel itself around the bath tube.

I wonder how far the C36 would get with its holding tank full of baking soda and viniger for propulsion.

Steve, after the pressure builds and you open the through hull you may find you have discovered a new way to get the boat going sideways!
John Meyer
Hilbre 2135

My tank fitting had a small crack that let just a little of the good stuff weep out and smell the whole boat up. A dab of 5200 on the threads and in the crack has been holding well so far. Good luck

You can add some oxygen treatment - we used the oxygen bleach - sort of like napisan (there are other cheaper non branded versions). We used this in the porta-potti, and the smell was non-offensive.