Holding Tank Odors

[Gary Solari]

We are experiencing a low level but detectable odor in the area of our holding tank. My boat is 16 years old and I have had it for 6 years.  I don't know of any maintenance done in the holding tank area. I have looked carefully and have not found any leaks in the hoses or the tank.  Nothing going into the bilge either.  We use a treatment every time after we empty the tank.  We usually fill and suck it out several times with seawater to "clean" it while at the marina waste removal site.   I heard from a friend that sometimes the odor can permeate the hoses to and from the tank after many years and changing the hoses will help solve the problem.  I don't have any other ideas at this time except to keep trying different kinds of treatments.  A second issue is that there is a significant odor the comes from the stanchion vent when the toilet is flushed.  
Any ideas or experiences would be very much appreciated.

Thanks

Gary Solari  
Windsong Hull #829
Bellingham, Washington (Puget Sound)

[Stu Jackson]

Gary

I recommend you go here:

http://shop.catalinaowners.com/detail.tpl?fno=20&group=327

Buy the book.

You'll get a lot of answers here that are already in the book.  We originally had her information posted on our FAQ section, but due to copyright stuff, she kindly asked us to remove it.

[SteveLyle]

Gary,

Take a couple of rags, soak them in hot water, and wring them out.  Put one on top of the holding tank, wrap another around your head hose (the intake hose is the most likely culprit - put it on at a low point, not the high end where it enters the tank).  Leave them on for a few hours.  Take em off and give them a wiff.  If they stink, you've found your problem.

After 16 years the hoses almost certainly need replacement.  This is a fairly easy job.  The tank is likely saturated as well - plastic is not totally impermeable to the odor.  If it's not too bad, you might try doing the hoses first and see if that gets the whole situation in the tolerable zone.  If not, you can always do the tank in the winter - it's a bigger job than the hoses, since it's glassed in.   You have to cut out the panel holding it in, then epoxy then panel back.

Steve

[David Sanner]

All good suggestions... don't forget the vent hose.

I replaced a few hoses but it wasn't until I replaced the holding tank vent hose that the odor went away.

[Vic Suben]

Another approach that worked for me was this.  I re-plumbed the lines to put a "T" in the sink drain line.  I connected the sink drain to one arm of the "T" and the head inlet hose to the other arm.  The third arm (or leg) is connected to sea cock.  By closing the sea cock, and partially filling the sink with the pressure (fresh) water system, I can use the water from the sink to flush the toilet.  From what I've read, the odor is caused by organisms in the sea water that die and stagnate in the hoses and tank.  Once the odor disappeared in Surprise I flush with fresh water after every two or three uses of the head.

Vic Suben
Surprise
Long Island Sound, NY

[PAUL T.]

Vic is right on the money...... salt water in the holding tank is the worst thing you can put in it. I fill the toilet bowl with the wand from the head sink, it's an extra step but not that tough. You need to Thoroughly clean your tank with fresh water and weak bleach solution. If you have the old black hoses replace them with the good white hose. Also replace the vent hose. My boat is totally oderless, even the vent hole at the stanchion smells sweet.  Good Luck PAUL......

[Mark G]

We flush with fresh water from the sink. Lake Michigan water also yields a smell if you use it in the head.

[John Langford]

A couple of folks have recommended replacing hoses. I would be interested particularly in  recommendations re replacing the vent hose. The original hose is normal reinforced water hose which has to be much more permeable than dedicated sanitation hose. Have folks found and installed a better type of hose?

Also, is the white sanitation hose really that much better than the black stuff that Catalina installs for the run from the toilet to the tank?

[Jim Price]

I also have "vent whiff"  and will be replacing the vent line from the tank and adding a new Sealand vent line odor cartridge in the system with new line to the stanchion.  The line from the tank to the "oder filter" will be the white Odor Safe stuff.  After the filter, I will just use regular hose for convenience of installation.  The white stuff does not bend very well in tight places so I will try this method first.

Another Fleet 13 member did this a couple of years ago and has never had an issue since.

The cartridge is a little pricey but when you have folks next to you, rafted or at dock, eating their dinner and you "burp" your vent, it don't make for friends!

[Ron Hill]

Gary : If your sanitary hoses are not "white", I recommend that you change them out to the "good stuff".  Maybe after 16 years even the white material gets saturated, but mine haven't in 18.  

The vent hose filter is also important.  

[SteveLyle]

John,

I did all my head hoses this spring, including the vent hose.  West sells a white vinyl hose and I used that.  It's a bit stiff - the only trick is to heat up the end of it with a hot air gun before inserting in onto the fittings - warm it up enough and it slides right on.

Steve

[wilsonlb]

I'm in the middle of replacing all the hoses in hopes of eliminating the same problem - and I will be adding a vent line filter.  Based on some stain patterns I thought I might also have a tank leak (I didn't), so I took the tank out too.

But here's the issue I've come across:  I'm installing the SeaLand OdorSafe hoses from head-to-tank and from tank-to-waste outlet (inland water setup).  The hoses are 1 1/2" and slide on and off my fittings easily.  Aren't I supposed to have to wrestle them on?  Do I have to replace my 1988 fittings, including deck fill, with newer models?

I did this project in two stages and have had some leaking around two connections that were double clamped.  I know I'm not supposed to use an adhesive, but might this be a fix?

Any similar experiences?

[John Langford]

Just replaced the vent line this weekend as recommended. I used Shields 3/4" white sanitation hose and the job was quite straightforward. The original PVC vent line was pretty polluted.

However, l  didn't entirely beat the problem. I think the hose leading to the macerator and thru-hull fitting may be the worst culprit. It is below the bottom of the tank and obviously would always have  nasty stuff sitting in it if even a bit was left in the tank. It is next on my list after we get back from the summer cruise.

Onward and upward!

[Ed Shankle]

I'm not so sure the vent filter is the way to go. If you check out the book referenced, I think the author doesn't recommend a vent filter, as it impedes air flow. I tried the filter for a couple of seasons and it didn't seem to help. However, I have since removed it, changed out the vent hose and altered the the path of the hose slightly, taking out the right angle so there would be a smoother up flow. This required some redrilling of the panel that the hose passes through. Also have been using the K.O. product referenced in the book. The combination has helped. I also think I have a saturated tank that I should replace, but the aroma is low grade enough so it isn't a priority yet.
I also think that regular use actually helps, as it introduces oxygen to the tank, which the "good" bacteria need. An anerobic state is what the "bad" bacteria like and those are the ones that create the aroma.

[Jeff Kaplan]

when i took possession of #219,1986, end of last season, the boat didn't just smell, it stunk. the boat was on a mooring for almost a year, and the po"s left the holding tank full, and the vented loop in the hanging locker was venting into the boat. before i let anybody into the cabin, i had to bring every one to the bow, i would go down below,open all ports and hatches and air out the boat. my wife couldn't stand it. the only solution was to completely replace the entire sanitation system. i got the 1 1/2" hose from an Australian co.,a.g.s., with branch in us for $5', less than west. if you get this hose, use shields fittings which have a smooth collar. regular barbed fittings won't work. you have to use a hairdryer to soften the ends and apply k-y jelly to ease the install. the rest of the hose bought locally. i increased the vent line to 3/4". i got the tank directly from catalina, exact one. i also replaced all the vented loops, and y valves. i was a very unpleasant job, but worth all the effort. also, i took off all cushions, sprayed them with febreeze, and let them sit in the sun. also i completely deodorized the inside of the boat. no more smell and now my wife and guests love to come on board. what a relief. e-mail me with any questions. good luck...jeff kaplan "sedona sunset".