Aroma

Or as my wife refers to it...."Stench"

Over the winter spent quite a bit of time and money totally redoing the black water system. New macerator, PVC piping for some of the system and all new hoses for the rest, larger venting. All trying to eliminate an intermittent aroma (stench). Not always but usually the aroma surfaced after a little rough water.

All seemed to work fine...until we encountered some rough water. Aroma may last 10 minutes to 2 hours and seems to be coming up the pilothouse stairs from below. Investigation shows no leaks, nothing obvious.

I have read of activated charcoal filters on the vent hose but not sure why this would help. Can't imagine odor being forced back from vent line.

Any thoughts? Ideas?

Thanks

Ken

Maybe the Head Mistress will pipe in. If you used hoses not designed for waste water, you could be getting odor permeating the hoses. Although, it would seem that the odor would be there no matter what the seas where.

maybe the rough water is causing waste water up into the vent line and it has a droop blocking the vent line?

Peggie will be along soon to give you some ideas on where to look for the source of the order. In the mean time buy her book. Only ten bucks for the Kendle version. That's a real bargain.
https://www.amazon.com/New-Get-Rid-Boat-Odors/dp/1892399784/ref=dp_ob_title_bk

I forgot to ask, what is the tank made out of?

ktdtx said:

Or as my wife refers to it...."Stench"

Over the winter spent quite a bit of time and money totally redoing the black water system. New macerator, PVC piping for some of the system and all new hoses for the rest, larger venting. All trying to eliminate an intermittent aroma (stench). Not always but usually the aroma surfaced after a little rough water.

All seemed to work fine...until we encountered some rough water. Aroma may last 10 minutes to 2 hours and seems to be coming up the pilothouse stairs from below. Investigation shows no leaks, nothing obvious.

I have read of activated charcoal filters on the vent hose but not sure why this would help. Can't imagine odor being forced back from vent line.

Any thoughts? Ideas?

Thanks

Ken

Click to expand...

My Silverton (1990) had what I believed was the original charcoal filter in the vent line. Heck......what did I care, the stink was outside the boat. This was exciting when I rafted with friends. Every time one of our two heads got flushed, that water entering the holding tank released an equal volume of ....well, treated air It was strong enough to make one's eyes water! The only time it bothered me was when I visited the rafted boat.

Finally Wifey demanded an end to my ......just call it chuckles. The replacement for the overpriced charcoal filter at West Marine was pennies short of a hundred bucks! But Wifey was adamant, fresh air was in demand by too many friends.

So my final fix was to purchase a water filter along with the needed charcoal filter to fill it and install it in series with the vent line. And every body celebrated

Ken,

In the process of doing the work you have so far, did you open up the tank and examine the condition inside? Have you rinsed the tank repeatedly until the rinse water is almost as clear coming out as it went going in? You improved the venting, can you describe how it is vented now?

There should be no way you are getting a smell from inside the boat unless you either have a leak in your piping somewhere, or if some of the hoses that are there are saturated. The other option is that there is a leak in the vent line.

Greetings,
Mr. kt. Perish the thought but is your holding tank cracked towards the top anywhere? Maybe where a hole/pipe penetrates? I vaguely recall charcoal filters are NOT recommended in the vent line.

RT Firefly said:

Greetings,
Mr. kt. Perish the thought but is your holding tank cracked towards the top anywhere? Maybe where a hole/pipe penetrates? I vaguely recall charcoal filters are NOT recommended in the vent line.

Click to expand...

Mr. RT, I question your last statement about charcoal filters not being recommended in the vent line. Many boat makers build them into the system for the express purpose of removing that wonderful odor that works its way up the vent line when the head is flushed.

For those of you still buying the $100 PVC filters from WM and others, there is a solution.....

The next time you remove the PVC filter, don't throw it away and replace it. Here's what you do:
==Before you start this, go to a pet store and buy a 1/2 gallon container of Activated Charcoal.
1. Cut the PVC pipe in half somewhere near the middle. Dump the charcoal inside the PVC into a plastic bag, seal it well and dispose of it.
2. Peel back the silvery plastic label for a few inches on both sides of the cut.
3. Cut out a section of PVC pipe that is about the same length as the assembled MALE and FEMALE connectors you're going to install below. This keeps the overall length of the fart filter about the same.
4. Install a slip-to-thread MALE connector on one half of the PVC pipe
5. Install a slip-to-thread FEMALE connector on the other end
6. Look inside each segment of the pipe and you will see a sponge filter near the end of the pipe.
7. Remove those sponge filters and wash them in soapy water.
8. Put the sponge filters back in place in each end.
9. Fill both ends of the PVC with the activated charcoal.
10. Screw the two PVC ends back together and reinstall you new filter in the boat.

The Activated Charcoal will cost about $10-$15 depending on where you buy it and is good for about 3-4 refills on the modified filter.

OTOH, avoid a charcoal filter altogether and find out why your tank is stinky in the first place. A charcoal filter could be considered simply an attempt to cover up a failure in either the design of the system or how it is maintained.

I think the best thing you can do is remove the filter. It just blocks the vent and prevents killing off the anaerobic growth which is what stinks. The vent needs to allow air into the tank. The more the better.

Manage the waste and it wont smell.
In my experience removing charcoal filters is the right thing to do for a number of reasons not least once they get wet they dont work and you risk being gassed in your own boat.
Smell out of a black tank is a sign of a battle between bad bacteria (anaerobic) and good (aerobic) being lost by the aerobic bacteria. Oxygen across the tank is vital in promotion of the good bacteria so here are some rules
dont use any chemicals - even to clean toilet, nothing...
if you can install 2 vents do as you set up air flow across the tank
In Australia its NappySan Oxy Action in the US its Oxy Clean, cloths washing powders - these products are cheap and encourage the growth of good bacteria in your tank - one scoop down the toilet every time you empty your tank.
Stick to that and your tank wont stink.
Happy to add more if you want.

Agree filters are a mask for the real problem...best to solve the root cause.
You might have residual solids left in the tank...several tank flushes w clear watet after one of those rough rides might help.
Many of us have had good results after using NoFlex head treatment...worth a try as it is reported to help clean up dirty tanks.
Can you figure out the source of the smell...vent line outside finding its wayback in...from the bowl itself...is it noticable in the bilge? ?

KTDX--

I know it must be frustrating trying to overcome this problem. And although we can chuckle about after it is fixed, there are no chuckles fixing it. So some more suggestions.

I believe the odor problem is related to your vent line and vents are an important part of your waste system. For example, if the vent becomes plugged, you risk the holding tank's collapsing during a pump out. I traced mine, it left the tank and disappeared into a wall on the hull's interior side. It took some time to get access but sure enough, there stuck in the line was an ancient charcoal vent filter.

If you get this far and can remove it, I suggest that you consider purchasing a new one or find some way to insert activated carbon in series with the vent. I can say with experience that vented air....if you want to call it air.... really reeks. My problem is behind me now. There may be other ways to overcome stench but I am a believer in activated carbon. Good luck and please let us know if you get it fixed. To be sure, others have a similar problem.

I think you said you addressed this in your re-plumbing of the system, but just in case....

It's really important that there not be any opportunity for residual standing water in hoses. Even the very best hoses, if left with standing black water in them, will start to stink after a few days or more. All the manufacturers say not to leave standing water.

We had a very elusive smell problem on our boat, and I finally realized that there is a down loop to a second manual pump for overboard discharge. Once you pump overboard, there is residual black water left standing in that down loop, and after a few days/weeks the stink gets through the hoses.

The solution was to simply flush some fresh water through the tank and pump overboard, leaving only highly dilute black water in the loop. It's a good practice anyway for keeping sludge from accumulating in the tank.

All smells are now gone.

The OP hasn't been back to give us any more information. I'm wondering if he might have a metal tank. Aluminum tanks last just a few years and stainless not a lot longer.

The tank is fiberglass.

Working to upload a photo or two of plumbing-PVC and hoses.
ALL hoses new this spring. Vent line enlarged from what it was before.
Red food color applied a couple times looking for leaks--none found.

Frustrating due to intermittent and transient nature.

Have started applying the "good bacteria" but won't really know until next rough water, which I try to avoid.
I could deal with the occasional "stench" (wife's description) BUT, I have a wife who describes it as "stench".

Thanks for all the input and variety of things to look at and try.

The person who did most of the work on the system suggested I do NOT let anyone talk me into putting a filter in the vent line--just something to clog and prevent/slow the outflow.

Top photo from couple months ago--work in progress.
Bottom photo is the hose used where PVC was not.

ktdtx said:

The person who did most of the work on the system suggested I do NOT let anyone talk me into putting a filter in the vent line--just something to clog and prevent/slow the outflow.

Click to expand...

I haven't found the vent filter to be much of a factor in our last three boats... except for dock neighbors and boats rafted on side from time to time.

Otherwise, not much impact on interior "aroma."

I think we've had to change the vent filter on this boat maybe once every 4 years or so... and it tells me when it's necessary. (Well, actually sometimes the neighbor makes a suggestion...)

I suspect it depends on more factors than just the filter itself: vent hose diameter, hose run length, maybe whether kinked, etc. And overflowing the holding tank, so that effluent travels up the vent hose and into the filter, would make it toast pretty quickly...

But at least in our boats, if there was any holding tank odor in the cabin, it's not had anything to do with the vent filter. (But Peggie's guidance and your specific situation trumps all that.)

-Chris

Boat odors are NOT all in your head OR your tank! Unless a tank is leaking, it is rarely if ever the source of odor INSIDE the boat because odor from inside the tank has only one place to go: out the tank vent. [FONT=&quot]So while frequent pumpouts, increased ventilation, various tank products may or may not have any impact at all on odor out the tank vent, using any or all of them to try to eliminate odor inside the boat is only chasing your tail …you’ll never catch it. So first we have to find the SOURCE of the odor 'cuz you cannot eliminate any odor until you first remove the source...it'll just continue creating new odor if you don't.

[/FONT]Permeated sanitation hoses are the most common source of odor inside the boat, but unlikely in your case because you've just replaced them...unless you tried to save money by going with cheap hose. I've seen that stuff permeate in less than 90 days.

Wet bilges in desperate need of a real cleaning--the kind of cleaning that requires real manual labor instead of just dumping some "miracle" product or bleach into 'em and calling it done--are another common source of odor inside the boat. A wet dirty bilge is full of bacteria and micro sea life which turn it into a real primordial soup that can make a whole boat smell like a swamp or even a sewer. That you experienced it after some serious rockin' and rollin' makes this one a good possibility.

But if your bilges are all dry as bones and clean enough to serve food on, that leaves trapped water somewhere...and you won't get rid of the odor until you find it, remove it and thoroughly clean out that area. 'Cuz trapped water is stagnant water that becomes that same primordial soup. You're saying that it seems to emanate from an area below the pilot house stairs...that gives you a head start on finding it because odors are always strongest at their source. You may have to do a little carpentry to open up that area, but that's where I'd start. And when you find it, clean that whole area thoroughly with detergent--NO BLEACH!...let it dry out completely...and then get rid of any residual odor by treating with PureAyre PureAyre .

And finally...at the risk of being accused of shameless promotion, take HopCar's suggestion and buy my book...it covers all this and more in detail. Amazon has it in both hard copy and kindle...click on the title in my signature to get to it.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

Poke your nose inside the anchor locker. Just a thought.

CPseudonym said:

Poke your nose inside the anchor locker. Just a thought.

Click to expand...

Good thought.

'Tis a good thought. But unless his pilot house steps are in the bow or he's wrong about where the odor seems to be coming from, prob'ly not the source this time.

The odor only seemed to "appear" after the boat had been tossed around a bit...that indicates some stagnant water was sloshed around, 'cuz it doesn't stink when it's still.

HeadMistress said:

'Tis a good thought. But unless his pilot house steps are in the bow or he's wrong about where the odor seems to be coming from, prob'ly not the source this time.

Click to expand...

I am sure I have asked this before, but I'm old and can't remember stuff...

You mentions a couple posts up to clean the bilge with detergent but not use any bleach. I understand using detergent (and scrubbing!) but why not any bleach? I know that bleach can be corrosive but I like using a 1-10 mix of household bleach in a spray bottle as a final cleaning step anytime I am cleaning an area where there has been mold or mildew or a black water spill. If it is rinsed well afterwards, why is that a bad idea?

In trying to track down the source of the smell, keep in mind that air can move about a boat in non-obvious ways.

We chased our tails for a while because of this. We would be certain the smell was from a particular cabinet, so cleaned the drain and trap for the ac unit in there. Then we were certain it was coming from another cabinet below which are the vented loops for the overboard discharge. I was sure it was from the vents and was about to remote plumb the vent breathers. Then we were sure it was coming from the forward equipment space because sometimes we would get a whiff when going down there.

Ultimately this last location was the source, but you could be sitting right next to it and still not be sure. The smell was wafting around enough to be detectable in all those locations because of air flow through voids in the boat, and diffuse enough to be really hard to nail down. But once we reasoned out how there was standing water in the hoses in the forward equipment space, all became clear. Flushing with water after pumping overboard completely solved the problem.

Also if it has not been mentioned yet look at your shower drain(s)

We had a horrible odor occasionally on a previous boat. Smelled like a head, but turned out to be an unhooked vent line from the gray water holding tank. They can smell as bad as a holding tank.

I agree that charcoal filters in the vent line are not a good thing. Instead, get fresh air into your holding tank. A vent to each side of the boat or install a Groco Sweettank air pump. We put one in a previous boat that had the horrible smell coming from the vent whenever the head was flushed. We had the Sweettank for 8 years, no smell whatever and no chemicals were used in the tank. Aerobic bacteria is your friend in holding tanks.

great reply Comodave - spot on.

Sure does take me a while to post photos.

Just to show the hose type used and the work in progress, this winter, with the PVC.

I agree, I have to find the source. I have a troublesome area of mid bilge that I don't really know how to access---believe it will require some deconstruction of the bed.
I guess I'll do what I gotts do.

Thanks for all the ideas & suggestions on an often discussed subject.

Ken

PVC pipe and Trident 102 hose, can't say you didn't use the best.
Polyurethane tanks good, metal tanks bad, fiberglass I don't know.
I would think a well made fiberglass tank would be good.

Peggie, can a fiberglass tank get permeated and smell? Should he do a rag test on his tank?