Heads inlet pipe smell

P4Paul said:
A real quick trick to clean out the inlet pipe is to close the seacock and take off the inlet pipe from the heads, drop in an Aqua Clean tablet, reconnect the pipe and leave it overnight. Do that a couple of times and your inlet pipe should be as clean as the day it was made.

I pop in a tablet every time we leave the boat for longer than a few days and no longer have any issues with eggy smells

when pumping the heads upon our return.
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That seems to have worked brilliantly for us. Chief closed the seacock, disconnected inlet pipe, raised pipe as high as possible then poured in AquaClean Tab dissolved in a small amount of water. Left it for 24 hours in upright position, wedged.
Previously the loo smelled sulphurous after a few pumps. (New boat to us, in Med) Now it's perfectly sweet. Will report back about how long it lasts.
Thanks P4 Paul!
 
WARNING: Old thread.
brownsox said:
... Chief closed the seacock, disconnected inlet pipe, raised pipe as high as possible then poured in AquaClean Tab dissolved in a small amount of water...
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What a palaver!

Just install a Jabsco Pump Strainer then dose with a chlorine based tablet. The effervescent NaDCC tablets I suggest for Protection from Bacteria in Water Tanks would work really well. Allow to fizz for a minute, then pump until you can smell the chlorine.
 
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I find it easier not to worry about it, since it disappears with regular use anyway. Installing a syphon break on the inlet along with a section of anti-odour hose seems to have reduced the smell to almost nothing, and only at the beginning of the season.
 
I've fitted one of these Jabsco strainers to midway in the inlet pipe loop last year. In the middle of the strainer you put in a small chunk of whatever flavour "toilet block" you prefer. Lasts about 4 weeks, longer if boat not used much. Smell completely gone: used to be bad on first few flushes. Standard "toilet blocks" too big for the middle of a Jabsco Pumpguard, hence cut in half. If I was designing the setup now I'd use a big Vetus strainer placed somewhere easy to reach on the inlet, save having to cut up little toilet blocks and firkle round awkwardly under the heads sink to reach the little Jabsco strainer.
 
Actually, no biological matter is required. The main source of sulfur is sulfate in the seawater (sulfate is reduced to sulfide when anaerobic bacteria use sulfate as an oxygen source). This is the ACTUAL problem and the reason the fresh water flush solves it. Much less sulfate.

The correlate is that fresh water flush doesn't work when the freshwater is very high in sulfate. Oh well.
 
I have fitted a Headomatic sanitiser just after the inlet seacock. Very happy with it - no smells at all from inlet hose or rest of system. Also loo always flushes with nice blue water which impresses guests.

I don't know exactly what is in the blue bullets, but I think there is something (sodium metabisulphite?) that kills the anaerobic bacteria that make the H2S.
 
VicS said:
Too late. I read half of it again before I realized it was beginning to sound familiar
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At least you read it before repeating the same answers from last time round :-)

Actually I do have an update. At the time of this thread last year I poured in bleach, left it and all was good for maybe 4 months? Then it slowly started to come back after lack of use for a few days, then after lack of use for a few hours and by a couple of months ago it was really bad. Repeated the bleach treatment about a month ago and all smelling sweetly since. Yes Yes the inline tablets would stop me having to do that....
 
laika said:
At least you read it before repeating the same answers from last time round :-)

Actually I do have an update. At the time of this thread last year I poured in bleach, left it and all was good for maybe 4 months? Then it slowly started to come back after lack of use for a few days, then after lack of use for a few hours and by a couple of months ago it was really bad. Repeated the bleach treatment about a month ago and all smelling sweetly since. Yes Yes the inline tablets would stop me having to do that....
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The Jabsco instructions state that you should not use bleach as it attacks the rubber valves and seals. I've no idea whether there's any truth in it though.

Richard
 
I've read elsewhere that another reason you shouldn't use bleach is that it only kills aerobic bacteria which are not smelly and actually help breakdown the contents of the holding tank. It is the anaerobic bacteria that cause the pongs.

Those headomatic bullets really are quite effective - I once opened up the inspection hatch of my holding tank while it was half full and had been fermenting for a day - it really didn't smell unpleasant at all - just reminded my of silage on the farm.
 
Ric said:
I've read elsewhere that another reason you shouldn't use bleach is that it only kills aerobic bacteria which are not smelly and actually help breakdown the contents of the holding tank. It is the anaerobic bacteria that cause the pongs.

Those headomatic bullets really are quite effective - I once opened up the inspection hatch of my holding tank while it was half full and had been fermenting for a day - it really didn't smell unpleasant at all - just reminded my of silage on the farm.
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I used to have a house with a septic tank that was illegal when we bought it, and had a mini sewage device installed. This pumped up dirty water from the bottom of the tank, and distributed it over a pile of chopped up corrugated hose. Once you got the timer settings right for your usage, you could shove your head under the lid, and there was zero smell, since the bugs grew on the corrugated pipe and dealt with the nasty stuff.
 
Peggy has earned her expereince the hard way. Let's consider a few things:

a. Every time I have changed a home toilet valve or ball it was clear to me that chlorine (only 1 ppm) had rotted the rubber.
b. The bleach treatment from pills or a does is at least 100-1000 times higher than this.
c. Depends on the type of rubber. Neoprene is pretty good with bleach, but nitrile is not. Both are common in heads.
d. Bleach is known to increase permeation in hoses.

So you can be a contrarian if you like, but you are rolling the dice. Perhaps if you overhaul frequently it is irrelevant. But bleach is also unnecessary if everything is operated correctly.
 
thinwater said:
Actually, no biological matter is required. The main source of sulfur is sulfate in the seawater (sulfate is reduced to sulfide when anaerobic bacteria use sulfate as an oxygen source). This is the ACTUAL problem and the reason the fresh water flush solves it. Much less sulfate.

The correlate is that fresh water flush doesn't work when the freshwater is very high in sulfate. Oh well.
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This was not what I found when I investigated it. See https://coxengineering.sharepoint.com/Pages/Toilets.aspx Sorry the layout of this item is so poor, at least on my iPad.

I did the work in Greece, where maybe the chemical constituents differ from UK. Could maybe justify being done again in home waters.
 
The anaerobic bacteria are using sulphate instead of oxygen to oxidise organic matter, so surely some ‘biological matter’ is required for hydrogen sulphide production?

OK, when in a closed system all the available organic matter is consumed, the bacterial remains themselves may provide the survivors with an organic food source for a while, but for sustained production an organic food source is needed.

In coastal and productive water that organic matter may come from the water itself rather than from the heads.

Or am I missing something here?
 
^^ Perhaps my point was a too fine. Let me explain.

Obviously some bacteria are required. Normally these can be expected to colonize the hoses, and even with occational bleach treatment, I doubt you will sterilize the system clear to the water and through the seacock. You could, but that's a lot of fooling with hoses and bleach. Since we close our seacocks when not on the boat (I hope) we can be certain these are anaerobic bacteria. The bottom line is that their don't need to be many organics or bacteria, or any, in the water itself. The problem with testing using clean bottles is that they do not mimic intake piping, which is not clean.

It isn't just seawater than can stink. The tap water at my marina smells of H2S when you first open the tap because the well is high in sulfate. The well does not smell (no bacteria). If kept in a clean water bottle it will not smell. The water straight from the pipe does not smell. But the water in the hose does because there are more bacteria and algae there. All that is required is to let the water run a little. It will also smell sulfurous in the tank unless you lightly chlorinate. Yes, the bleach kills the bugs. However, even if the water has already turned, just a few ppm bleach will eliminate sulfide by oxidizing it back to sulfate, which we cannot smell or taste.

Low sulfate tap water, watermaker water, or rainwater are well know not to smell when used as head intake. Could fecal mater get into the intake as a result of pump leakage? Almost certainly some does.

The other documented observation is that holding tanks smell more when flushed with seawater than with freshwater. Same reasons. There is a LOT more sulfate in seawater than there is in sewage, and seawater inhibits aerobic bacteria. In fact, at least half of the sulfur in poop comes from the tap water you drank, not the food. Something to consider.

A lot of variables, to be sure.
 
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