Hugely smelly holding tank

and in the mean time bung the bloody up....
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Whatever you do DO NOT BUNG IT UP!!!!!!!!!!!!!

This could make matters worse as you might collapse the tank /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif

Then the s**t will hit the fan.....
 
Hired a caravan once with a cassette toilet which had a shot of a blue liquid added everytime it was emptied, ready for the new charge. When emptying at the toilets it never seemed to smell that bad and the blue liquid, whatever it was must have been doing its job. Why not try that?
 
I wish I had the action in the holding tank. Despite 38mm vents, fore and aft, the tank stinks after 1 day of use. I don't know how to solve the problem other than filling the tank with sea water and draining every time I go to sea.

it should not stink with those vents. Suggests you have a blockage somewhere and it has not drained properly. You can get filter for the vent, although strictly speaking are not really necessary if you empty regularly.

BTW, hope you sorted out your stern gear problem.
 
I wish I had the action in the holding tank. Despite 38mm vents, fore and aft, the tank stinks after 1 day of use. I don't know how to solve the problem other than filling the tank with sea water and draining every time I go to sea.

This is one product Peggie Hall endorsed and it is available in the UK. Why not give it a try. It sounds like your 38 mm might be too long and tortuous.
 
As most posters have said you need to have adequate air to the holding tank, but it could be that the source of the smell is elsewhere.

You mention that you pump it through with salt water. If salt water stands for any time in your inlet hose you'll get a pong of 'rotten eggs' from decaying algae. Always pump the inlet hose through with fresh water when returning to the dock. My old boat has the sink drain out through the toilet inlet through hull. I put a bucket of water into the sink, close the through hull and drain it into the bowel and pump through to the holding tank. Simple and effective.

The other source could be waste lying in the pipes between the bowel and the holding tank We all tend to not pump enough to get the discharge all the way along. The smell will permeate through the pipes especially if you don't have (or even need) toilet grade pipes. I once forgot to discharge when at sea and probably had some waste in the pipes which led to an awful smell. I pumped through with fresh water on a daily basis for a week or so, added some Simple Green (which is eco friendly) to break down any hardened remnants and lubricate the pump. Worked a charm. Otherwise I use no additives and my loo smells sweet.
 
You mention that you pump it through with salt water. If salt water stands for any time in your inlet hose you'll get a pong of 'rotten eggs' from decaying algae.

This is simply not true. I carried out a series of experiments storing seawater in a variety of conditions, reported in YM and shown on my website. Seawater does not smell at all, even after a month. Any smell comes from contamination by human faeces.

Sorry, pics are no longer on my website. They were on a previous version of it.
 
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Mine does if I don't pump with fresh water and it is a different smell to that from faeces in the pipes.
 
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Peggie Hall an american lady we so dearly miss waxed lyrical on this subject and has written books telling how to live with holding tanks. Her latest book about Boat Odors is in Print and available from Amazon however the earlier book is available on various sites Fact V Folklore .

Your basic problem is ventilation of the air space of the holding tank. Your breather is too small and not working.I believe Peggie suggests 1" breathers in her latest book with breathers from each side of the boat if possible so that the tank is maintained in an aerobic state.

Read Ms Halls book as above and although the treatment chemicals she refers to are not readily available you can get substitutes in some marinas and also the B and Q warehouse which it sells for cesspits. I suspect Lee Sanitation may also be able to help.

As my good friend Peggie says.....holding tanks should not smell!!!!

I get a 404 on that link and would like to a have a look, any alternatives?
 
This is simply not true. I carried out a series of experiments storing seawater in a variety of conditions, reported in YM and shown on my website. Seawater does not smell at all, even after a month. Any smell comes from contamination by human faeces.
I hate to disagree with you, but my experience is different. Bacteria multiply in the inlet hose, causing a smell of Hydrogen Sulphide when flushing. Bleach in the bowl does not cure it, but a Milton tablet in the inlet filter does.
 
I hate to disagree with you, but my experience is different. Bacteria multiply in the inlet hose, causing a smell of Hydrogen Sulphide when flushing. Bleach in the bowl does not cure it, but a Milton tablet in the inlet filter does.

Not tried the Milton tablet, but I agree with Nigel. The "not used" smell (from the inlet pipe) is different from the "sewage" smell (from the outlet pipe). SWMBO is away for her regular 3-week trip to visit her friend in Corfu at the moment and I flush her heads (unused) twice a day to keep fresh seawater in the inlet pipe. If I don't do this when she comes back her heads smell (of Hydrogen Sulphide) for several days.

Also agree that more air is the key to killing the "sewage" smell. According to Peggie there are two kinds of bacteria that break down waste; aerobic and anaerobic. Aerobic bacteria need lots of fresh air of course and they break down waste very effectively but do not produce much of a smell. Anaerobic bacteria hate fresh air and they also break down waste very well, but they produce a terrible smell. This is why you need good ventilation to the tank - but venting outside the boat of course. When in a marina or port where we have access to toilets on shore we leave the pump-out deck fitting off the holding tank to encourage a circulation of air down the dip pipe and back out the vent. Our holding tank does not smell.
 
I hate to disagree with you, but my experience is different. Bacteria multiply in the inlet hose, causing a smell of Hydrogen Sulphide when flushing. Bleach in the bowl does not cure it, but a Milton tablet in the inlet filter does.

But it isn't seawater that is smelling, it is waste that is passing the inlet valve, going upstream. The valves are the simplest flap valve imaginable, nowhere near leak tight. Waste is spread all over the cylinder walls, the piston seal is a badly fitting O-ring, so contamination is inevitable.
 
I don't have the information or the article with me, all at home on the laptop. I took samples of seawater in light and dark bottles, the light ones kept in the heads, the dark ones in the bilge. The bottles were 1.5 litre plastic drinks bottles. I left them for 24, 48, 72 hours, 1 week and one month. On opening them not a single one smelled of H2S, or anything else.
 
But it isn't seawater that is smelling, it is waste that is passing the inlet valve, going upstream. The valves are the simplest flap valve imaginable, nowhere near leak tight. Waste is spread all over the cylinder walls, the piston seal is a badly fitting O-ring, so contamination is inevitable.

I am with Nigel on this.

My Lavac flush comes from a sea chest inlet and when I return to my boat after a month standing with the inlet seacock closed I get the same Hydrogen Sulphide smell until after about 20/30 initial flush pumps.

I also get the same smell from my sea water deck wash outlets first time use after a time of non use.

In both cases the smell disperses after the initial flush through.
 
But it isn't seawater that is smelling, it is waste that is passing the inlet valve, going upstream...

I agree that it is some form of bacteria that causes the problem, but it doesn't necessarily come directly from the outlet. We have a manual heads on board that hasn't been used for a couple of years, but I always open it up in case we have a power failure. It stinks, put Milton tablet in the inlet filter*, pump until chlorine smell detected, leave it a few minutes. Doesn't smell again until next time.

* http://www.force4.co.uk/873/Jabsco-...3-4--Hose--Course-Stainless-Steel-Filter.html
 
But it isn't seawater that is smelling, it is waste that is passing the inlet valve, going upstream. The valves are the simplest flap valve imaginable, nowhere near leak tight. Waste is spread all over the cylinder walls, the piston seal is a badly fitting O-ring, so contamination is inevitable.

This might be true with some modern single cylinder toilets however you still get the pong in Vacuflush.....SL401......and Lavac where there is NO mixing of in and out within the toilet system as the incoming water cannot be contaminated in the boat. Mind you heaven knows what happens outside the boat if sitting in still water. As most of my friends with Vacu flushes have holding tanks then this risk disappears. However they generally fit Fresh water flushing and the pong goes away! Some others fith a tee at the inlet to fill the inlet with a vinegar solution when leaving the boat.
 
It may be that when the holding tank is flushed not all of it goes out. Some may remain inside to fester if the outlet from the tank itself gets intermittently blocked.
I had this baffling problem with one of my tanks. It was discovered that the previous owner had allowed a face flannel to be flushed into the tank via the heads. Therefore, if the flannel drifted towards the outlet hole it partially blocked it, causing the problem. The offending flannel was fished out. The tank repeatedly flushed with fresh water and then a vinegar solution added. Then a bit of sailing in rough conditions. Then flushed out. Then rinsed again with fresh water twice. Problem cured.
 
our holding tank vents into the anchor chain locker. never had a problem even with the holding tank nearly full after stays in a marina. however been away for two weeks and having drained the lavac by pumping with the lid open i thought i'd reprime the system. the first panful of water pulled in was appalling - no smell but filthy and full of shrimps. two flushes later its all clear but i'm amazed at the crud you can get in an inlet pipe in hot weather
 
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