Holding tank smell

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Kantara

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Oh what a lovely topic!
We have two heads aboard, one old fashioned one discharging straight overboard and one with the option of going into a holding tank.
Acting on the best advice of people like Head Mistress and Nigel Calder, I have been in the habit of pouring some vinegar into the heads from time to time and this has resulted in beautifully sweet smelling conveniences. However, this year we have found ourselves stormbound in marinas more often than in the past and have used the holding tank more. As a result we have been pumping vinegar into the holding tank. The result has been some foul smells beginning to appear in the cockpit locker where the vent is. Changing the filter has made no difference.
We have reached the conclusion that it is because of the vinegar which has killed the bacteria that works on the effluent. Is this possible, and if so, how do I get rid of the smell.
Someone has suggested that the holding tank is just like a sceptic tank and the best solution is to throw a dead rabbit into it!
Presumably there is an alternative (hugely expensive) product that can be used.
Any ideas? This smell is coming close to ruining our marriage!
 
"We have reached the conclusion that it is because of the vinegar which has killed the bacteria that works on the effluent."

Nope...it's bacteria breaking down waste anaerobically that's producing the odor. If all the bacteria were dead, there wouldn't be any.

Apparently, you aren't using anything else in the tank BUT vinegar. However, its purpose is not to eliminate odor, but only to prevent mineral buildup in the lines. You can prob'ly cut back on it to just a cupful once a week...but you need to use one of tank products that prevent odor (they are not expensive). I don't know what's available in the UK, but one of the best here is an import from Norway called Odorlos.

However, I'm a bit confused by this: "The result has been some foul smells beginning to appear in the cockpit locker where the vent is."

The tank is vented into a locker? Not outside the boat? If so, that MUST be changed. All waste tanks MUST be vented to the outside of the hull for two reasons: 1) methane gas is flammable...2) those smelly gasses that are destroying your life are sulphur dioxide and hydrogen sulfide, both of which are toxic and will make you very ill--even kill you in high enough concentration.

However, before you do anything, I suggest you read "Sanitation Guide" on the Tek-Tanks site at http://www.tek-tanks.com/sanitation/sanitation_index.html so you'll know what to do to cure the problem (it prob'ly would have been better if you'd read it BEFORE you installed and plumbed the tank).

I'll be glad to help you sort out the specifics of any changes you need to make.
so you'll know what you need to do to cure the problem:
 
Oh dear, that is a worry. The tank was installed by a 'professional' company and I specifically asked if it was OK to vent into the cockpit locker. They were the same people who suggested the dead rabbit! They strongly opposed any suggestion of adding any other chemicals to the tank to remove the smell. I will be taking your points up with them.

In the meantime, as the boat will be coming out of the water soon, would it be ok to flush the holding tank out with fresh water. If so, how do I protect it from frost?

Many thanks for your invaluable advice
 
You might want to refer the "professional" to the Tek-Tanks Sanitation Guide as well! I don't know what EU and/or any UK regs require...but on my side of the pond, venting to the outside of the boat isn't just desirable, US and Canadian Coast Guard regs REQUIRE it, for the reasons I posted above. There was story in the news a few weeks ago about a spill in a bilge of a cruise ship that killed several crewmen: (unfortunately it's old enough that this was the only link to it I could find that still worked): http://www.onlinelawyersource.com/news/workers-cruise-ship.html

That your tank isn't venting overboard is definitely the reason why your boat stinks...all the odors from inside the tank are going into the boat. Re-routing the vent to send them overboard is the first part of the solution...improving the ventilation by making the vent as short and straight as possible is the second part...and using a tank product is the third.

Btw...is your tank a rigid tank or a bladder? I'm afraid to ask what type of hose these so-called "pros" used....
 
Why on earth would any "professional" fit the vent to the inside of the boat?
The mind boggles!
Would you fit the fuel tank vents to the inside?
Dreadfull.
Joe
 
Holding tanks and Septic tanks really can't be compared.... and I wouldn't recommend a dead rabbit in either! I won't go into the differences here, just take my word for it.
I have a holding tank (and a septic tank, for that matter...but not on the boat!) and the previous owner installed a Purytec device on the flushing water inlet to the bowl. I don't know what the Purytec cannister contains, but it's a soluable product that dissolves a bit on every flush.
It dispenses a small amount of blue coloured ...erm...something.. into the water and it smells like the sort of chemical used for chemical toilets..Elsans and the like.
I imagine it's killing off the bugs. (The headmistress will enlighten us all, I'm sure on the specifics of this!)
I would hesitate, perhaps, on dumping this 'soup' at sea; being unsure how sea life would take to 'Elsan' fluid. But for pumping out I think it's fine. It also leaves a not an unpleasant aroma in the heads plus a blue flush in the bowl.
Venting into the cockpit sounds horrendous, and I think others have commented adequately on this.
Happy flushing!!
Cliff
 
I know the problem.

I think it is all about aerobic and anaerobic bacteria. The anaerobics cause the smell.
Apparently there are a number of aerobic treatments on the market but I was told that putting some fresh yeast (mixed with tepid water) into the tank would solve the problem.

I tried this during the summer when the stink was particularly unpleasant and it worked a treat. (Last year I relocated my office to a 64 foot narrow boat so living with smelly heads was not really an option).

I now get 50 grammes of yeast from Sainsbury's every two weeks or so (cost 16p) mix it with tepid water, let it stand for a few minutes to start bubbling and then pour it down the loo. Apoparently, the bacteria in the yeast creates oxygen and breaks down the waste and effectively eats the anaerobic bacteria that causes the smell.

It is a cheaper and more environmentaly friendly solution to using chemicals.

NB This solution works only if the system is clear of chemical treatments that contain formaldihide, so it is best to start the treatment a few days after a pump and rinse out of the holding tank.
 
Chemical products are not only damaging to the environment when you dump the tank at sea, but also wreak havoc in sewage treatment plants and septic tanks when pumped out. That's prob'ly not as big an issue over there as it is here, because there aren't nearly as many tanks in use there...but as more and more waters require boats to hold, it's likely to be.

Additionally, if you're using one of the chemical intake inline chemical cartridges, I'd be very careful not to use any other chemical in the tank--especially since you don't know what chemical is in the cartridge..'cuz you could end up with a lethal combination.

Yeast isn't something I'd recommend either. As it "outgasses" it may help to keep the environment in the tank more aerobic, but those gasses have to go somewhere...and if the tank vent should ever become blocked--which is not uncommon on sailboats--they'll pressurize the tank...with potentially disasterous consequences (if we ever have the opportunity to visit over pints some day, I'll tell you the story of a friend who decided to use yeast to re-start the septic tank at his summer home...hilarious in the telling, but NOT funny when it happened!).

If you want to try something a bit out of the ordinary, try a bit of high nitrate fertilizer instead. Nitrates promote oxygen release from organic matter--iow, from the waste itself--helping to maintain an aerobic environment in the tank. In fact, nitrates are the active ingredient in the Norwegian product Odorlos I mentioned above. When used as directed, it's exceptionally effective at eliminating odor out the tank vent.

Which brings me to another point: unless a tank is vented inside the boat, or is leaking, the holding tank is rarely if ever the source of odors inside a boat...'cuz unless it's leaking, odor from inside the tank has only one place to go: out the tank vent. So the fact that you may not have any odor INside the boat is no guarantee that you aren't gassing every living creature downwind of you every time you flush the head...it may only mean that your tank is vented to keep the odor away from you.
 
In the Water Industry Calcium Nitrate injection is often used to provide oxygen to enable the bacteria to much the smell producing bits. There various proprietary names available but they're all OK to dump to the marine environment because all they do is provide oxygen. OK eventually if we all use it and stay within a small area for a few tens of millions of years there'll be a small chalk deposit but that's not an environmental hazard.


Best way is to have two vents - one at each end of the tank (WHICH SHOULD BE RIGID TO ALLOW A PERMANENT AIRSPACE) - Oops sorry didn't mean to shout - that way you have a constant flow of air through the tank and no pong.

A Lady called Peggy Hall used to be the world authority on this in the states - the name Peale Products comes to mind call 1-800-352-5630 plus country code according to my old directory she published a book.

Fair winds
ken
 
[ QUOTE ]
The lady you are replying to IS Peggy.

Calcium nitrate introduces no Oxygen to the equation, so you'd better explain that one.

[/ QUOTE ]

Sometimes I think it would be easier to change my name from Peggie to "Peggy."

Hi Ken! Thanks for the plug! /forums/images/graemlins/smile.gif However, you're just a WEE bit behind the curve. I sold the Peal Products product line of products to Raritan Engineering in 1999...the 800# you posted now goes to them. Selling my company finally gave me time to write the book I'd been threatening to write for years. It was released in 2003....the link in my signature goes to it on my publisher's site.

I dunno whether nitrates and calcium nitrates are the same thing...but I do know that nitrates don't PROVIDE oxygen, they promote oxygen release from organic matter. The net result is the same, though: aerobic conditions in which odor can break down odorless-ly.
 
go on then. make me incredulous as to the equation wherein nitrates introduce oxygen into the equation. Anaerobes I could understand, but not aerobes
 
All organic matter contains some oxygen...nitrates don't introduce it, they extract it. Lawn fertilizer that includes nitrates/nitrogen does the same thing for the soil, encouraging healthier grass and plant growth.

Maybe an organic chemist will jump in and explain it.
 
Sorry, I have been out of touch for the last few days.
Yes, the tank is rigid - but it is made of stainless steel and according to the Tetra tanks site that is a no-no. I suspect that the seams are beginning to go so will be talking to the supplier.

This has been very helpful indeed. The only question remaining is whether I should try to flush the entire tank out with fresh water before the boat comes out of the water.
 
Yes...with lots and LOTS of fresh water. Not only the tank, but the whole system. This is done by disconnecting the head intake from the thru-hull (DO close the seacock first!) and sticking it into multiple buckets of clean fresh water. Don't forget to turn the y-valves to flush out the overboard lines too.

'Twouldn't hurt to put a quart of white vinegar into the last bucketful.

If you plan to winterize, flush the antifreeze through to the tank via the intake hose too. Then, leave all seacocks open after the boat comes out.

Based on everything you've said about your so-called "professional" tank installation, the only thing I'd want from them is a full refund!
 
nitrates make grass and plants grow greener, because they are an essential element for their growth, not because they contain or bring extra oxygen to the growth.

While all organic materials do contain some oxygen, it's largely irrelevant. Calcium nitrate does not oxygenate. I used to be a molecular biologist, so understand more than a bit about organic chemistry, I studied it for years, and still can't see the equation that calcium nitrate will introduce oxygen.

Calcium nitrate is injected into waste water management plants to scavenge H2S (hydrogen sulphide) which is the bad egg gas smelly stuff, not to introduce oxygen.

(Organic chemist jumping in, and explaining that a lot of twaddle is being posted!)
 
Brendan, I only know that the active ingredient in Odorlos is nitrates--confirmed by their MSDS, and that Odorlos claims it prevents odor by promoting oxygen release from the waste (one would THINK they'd know!). It does do an excellent job of preventing odor...but if that's not how it accomplishes that, how DO nitrates prevent odor???
 
Well, Brendan, I guess you weren't a very good organic chemist or molecular biologist or you would know that
a) not all organic componds contain oxygen. By definition, all organic compound contains carbon, but may or may not contain oygen.

b) nitrate ion contains 3 atoms of oxygen

c) how does Ca(NO3)2 scavenge H2S, by adsorption; I don't think so. By reaction; probably, in which case oxygen might be released. If you want to discuss this further, I'll check with some other chemists. I'm a bit rusty.

c) it's the nitrogen in nitrates which fertilizes, so their must be a breakdown of the nitrate to release nitrogen AND oxygen somewhere in the process.

AW BSc (Hons) Applied Chem, MRSC, C.Chem and many years in field of analytical chem. Who's talking twaddle? /forums/images/graemlins/smile.gif

p.s. thought you'd like to know that calcium nitrate is an inorganic compound, as it does not contain carbon, (but it does contain a lot of oxygen!!!).
 
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