Nasty Smell after flushing loo. Fresh water system

My boat has Lee Sanitation charcoal filters on the vents , I get no smell and I have not changed the filters in the last 7 years.
 
Hi Peter. I vaguely remember that there is a type of piping/tubing for marine WC outlets that greatly reduces this as the pipework gets older. They cheaper piping gets lined with some chemicals that smell but is less of a problem on salt water flush systems. I can't remember the name of it but remember replacing the WC outlet hoses on a previous boat which solved this problem.
 
oceanfroggie said:
Hi Peter. I vaguely remember that there is a type of piping/tubing for marine WC outlets that greatly reduces this as the pipework gets older. They cheaper piping gets lined with some chemicals that smell but is less of a problem on salt water flush systems. I can't remember the name of it but remember replacing the WC outlet hoses on a previous boat which solved this problem.
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You have to use sanitation quality hoses for any pipework that contains toilet waste. Standard bilge pump hose gets porous over time and whilst it may not actually leak waste, it will allow odour to escape. This is particularly the case with pipes that don't have much of gradient allowing waste to collect in them. But I don't think this is the OPs problem which sounds very much like odour escaping from the vent pipe. To deal with this, every time we leave the boat, we always fill the holding tank with a good amount of fresh water mixed with a waste tank chemical designed to break down the waste and then flush it out the next time we go to the boat. That seems to keep the odour under control
 
oceanfroggie said:
Hi Peter. I vaguely remember that there is a type of piping/tubing for marine WC outlets that greatly reduces this as the pipework gets older. They cheaper piping gets lined with some chemicals that smell but is less of a problem on salt water flush systems. I can't remember the name of it but remember replacing the WC outlet hoses on a previous boat which solved this problem.
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Thanks Noel,

I would have thought that given the high build quality on the T51 (it was Sealine's Flagship at the time I believe) that they would not have compromised with cheap pipes!
 
PEJ said:
Thanks Noel,

I would have thought that given the high build quality on the T51 (it was Sealine's Flagship at the time I believe) that they would not have compromised with cheap pipes!
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You never know so its worth checking. Any pipes between the toilets and the holding tank and from the holding tank to any outlets should be sanitation quality and these are generally white in colour. On the other hand bilge pump pipework is generally clear so its easy to tell the difference
 
bumpy_the_dog said:
The book has arrived and you're right...it is well worth 12 quid. It's really well written and informative, so much so that I'm well on the way to becoming a bog bore.
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OK Bumpy! I am off to the boat soon with my biological washing liquid in one hand to carry out the advice on here. If it does not work I'll be back to you for help. :)
 
PEJ said:
I have just spent the last half hour reading back through the many smelly toilet threads seeking a solution to my problem and I think I have gone from having no clue to having too much information! Can anyone help me reduce it down to the relevant facts?

I have two fresh water electric flush toilets on my 12 year old Sealine T51. If I am out in the cockpit or even the pontoon I get a nasty smell when the toilet is flushed. You can smell it inside too but not quite as bad. It is NOT the rotten eggs smell it is a pungent sewer type smell. Like a nasty f@rt but with a chemical edge.

I read about the vent pipe to the tank and the pipe that goes to the pump out. I have never opened the pump out cap in all the time I have had the boat (1 year). So I am guessing now that the smell comes from the vent on the holding tank. Does that sound right? How I do stop it?

Her indoors has been chucking bleach down the loos before we leave the boat. I read that that is not a good idea. Could the bleach and the smell be related.?
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I had quite a bit of trouble with nasty odours out the vent pipe when flushing since the boat was new (Boat nearly 3 years old) , but have eliminated them for the last 12 months, I found;
Adding chemicals did help a bit but this tends just to attempt to mask the odour and they may kill "good" bacteria that kill odours, I now use nothing.
The tank needs good ventilation through the vent (important!) Filters are not recommended and only to be used as a last resort as the smell will be contained in the tank and could leach into the bilge, lines then into the interior of the boat, also they need changing and can fail if they get wet.
Vent pipe was far to long and not getting direct fall into tank and water was getting stuck in vent pipe partially blocking the vent line (factory installed by Beneteau) shortened this by abt 2 foot, also sludge was accumulating where the vent went into the tank as I would only empty the tank when it was full to get value for money for the chemical, now I empty the tank when ever able, pump in 4 toilet bowls of water into the tank, slosh around pump out then leave it ready to use with one toilet bowl of water left in the tank (make sure your tank and hoses are clean), every now and then I stick the hose into the vent though hull, and hose out to ensure nothing is fouling the vent line.
There may be a bit of smell just after the tank is emptied, this will depend on how full it was and how clean your tank and lines are.
Hope this helps
 
Sydneysider said:
I had quite a bit of trouble with nasty odours out the vent pipe when flushing since the boat was new (Boat nearly 3 years old) , but have eliminated them for the last 12 months, I found;
Adding chemicals did help a bit but this tends just to attempt to mask the odour and they may kill "good" bacteria that kill odours, I now use nothing.
The tank needs good ventilation through the vent (important!) Filters are not recommended and only to be used as a last resort as the smell will be contained in the tank and could leach into the bilge, lines then into the interior of the boat, also they need changing and can fail if they get wet.
Vent pipe was far to long and not getting direct fall into tank and water was getting stuck in vent pipe partially blocking the vent line (factory installed by Beneteau) shortened this by abt 2 foot, also sludge was accumulating where the vent went into the tank as I would only empty the tank when it was full to get value for money for the chemical, now I empty the tank when ever able, pump in 4 toilet bowls of water into the tank, slosh around pump out then leave it ready to use with one toilet bowl of water left in the tank (make sure your tank and hoses are clean), every now and then I stick the hose into the vent though hull, and hose out to ensure nothing is fouling the vent line.
There may be a bit of smell just after the tank is emptied, this will depend on how full it was and how clean your tank and lines are.
Hope this helps
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Ah ha! Here's an opportunity for Bog Bore to promote the seminal tome "Get Rid Of Boat Odours"!

According to the author it seems you're on the right track. Apparently there are two types of bacteria battling it out to predominate in sewage. Anaerobic (prefers an airless environment) bacteria which are the smelly baddies, and aerobic bacteria which are the goodies and only produce odourless CO2. A free flow of fresh air through the holding tank vent line will allow the aerobic bacteria to predominate and prevent smells even without any treatment. Most boat manufacturers see the vent line as only having to be big enough to prevent the holding tank collapsing during pump out. The vent line should be as short, wide, straight and horizontal as possible so that the heavier than air CO2 produced by the "good" aerobic bacteria can be removed and replaced by fresh air...therefore filters are counter productive.

Incidentally, the holding tank venting problems on heeling sail boats are much more severe than on motor boats...so they're the ones that really deserve the title "stink boats"!

By the way, I'm collecting my new (to me) Antares 30 on Monday so I'm sure we're both looking forward to a lengthy correspondence on holding tank management!
 
Thanks again for all the posts on here.

I followed the advice on Friday and I am pleased to report no horrid smells when we flush the loos any more!

The tank gauge is useless, it does not work at all so I have to ignore it, with that in mind I would pass on the following two tips.

Time how long it takes to empty the tank. I filled it up until it overflowed and then got the stopwatch on the pump. In my case it took 3 mins 15 secs to empty. There was a definite change of tone from the pump when it emptied the tank. From now on I will have to time the pump outs to gauge how full the tank was and hopefully get a feel for how much usage equates to how full the tank is.

Time how long it takes to fill the tank with water from the hose. In my case it took 7 minutes. At first I could not believe the tank was so big that it took so long to fill it but after a few empties I just went and watched telly for 6.5 minutes while it was filling!
 
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PEJ said:
Thanks again for all the posts on here.

I followed the advice on Friday and I am pleased to report no horrid smells when we flush the loos any more!

The tank gauge is useless, it does not work at all so I have to ignore it, with that in mind I would pass on the following two tips.

Time how long it takes to empty the tank. I filled it up until it overflowed and then got the stopwatch on the pump. In my case it took 3 mins 15 secs to empty. There was a definite change of tone from the pump when it emptied the tank. From now on I will have to time the pump outs to gauge how full the tank was and hopefully get a feel for how much usage equates to how full the tank is.

Time how long it takes to fill the tank with water from the hose. In my case it took 7 minutes. At first I could not believe the tank was so big that it took so long to fill it but after a few empties I just went and watched telly for 6.5 minutes while it was filling!
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One thing you could consider is treating the holding tank.Check out the product Odorlos which is available from Amazon and chandleries.
 
Interesting smelly thread!
My boat is ten years old and we have had it from new.
Regular users of Odorlos but that seems useless for long term sludge.
The suggestion about bio washing stuff seems sensible so I am going to give that a go.
Has anyone found a contractor to do a proper clean of the black tank? That or some magic 'nasty' solution?!
 
Ban the bleach! Assuming you have a separate water tank for the freshwater flushing, put the pink stuff from the camping shop in it. Every time you empty the holding tank, chuck some LooBlue in and all your problems should go away.
 
aviator said:
Interesting smelly thread!
My boat is ten years old and we have had it from new.
Regular users of Odorlos but that seems useless for long term sludge.
The suggestion about bio washing stuff seems sensible so I am going to give that a go.
Has anyone found a contractor to do a proper clean of the black tank? That or some magic 'nasty' solution?!
Click to expand...

Sewage smells and the big sludge
________________________________________
I managed to get my hands on some of the Noflex Digestor (not an easy task from New Zealand) and have been using it for the last 2 months. The smell in the boat has almost completely gone and 2 days ago the waste gauge started working again. It has not worked since June last year despite 33 pumpouts in 9 months (many with fresh water flush afterwards) while we travelled half of the Great Loop, and since we brought the boat back home. If I needed convincing the stuff was cleaning out the whole system, this has done it and I am going to get my hands on some more.

Also we are pumping out via the macerator (legal here) and there is no brown trail in the wake and no smell during discharge. The only way I can tell that the tank is empty is by watching the amp draw of the macerator (18A under load - 2A no load).

The other good thing about it is that you add it as you go, so if you have an early pumpout you are not wasting any.
__________________
Loopy Kiwi
2003 Silverton 453PMY
Auckland
New Zealand
http://www.loopykiwi.blogspot.com
 
Sea Q said:
Sewage smells and the big sludge
________________________________________
I managed to get my hands on some of the Noflex Digestor (not an easy task from New Zealand) and have been using it for the last 2 months. The smell in the boat has almost completely gone and 2 days ago the waste gauge started working again. It has not worked since June last year despite 33 pumpouts in 9 months (many with fresh water flush afterwards) while we travelled half of the Great Loop, and since we brought the boat back home. If I needed convincing the stuff was cleaning out the whole system, this has done it and I am going to get my hands on some more.

Also we are pumping out via the macerator (legal here) and there is no brown trail in the wake and no smell during discharge. The only way I can tell that the tank is empty is by watching the amp draw of the macerator (18A under load - 2A no load).

The other good thing about it is that you add it as you go, so if you have an early pumpout you are not wasting any.
__________________
Loopy Kiwi
2003 Silverton 453PMY
Auckland
New Zealand
http://www.loopykiwi.blogspot.com
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A very warm welcome to the forum. How about some pics and a thread on your cruising ground? :)
 
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