Poo Tank Smell

[DBA Forum (B) - Kevin Wade]

We have a plastic Vetus 390L black tank. It has a Vetus carbon filter to supposedly refine any air emanating from the tank as it is filled. This has clearly stopped working and the stench is quite vile when the toilet is flushed forcing air out.

Disregarding the carbon filter, what can I do to the tank to "sweeten" the inside up? Brewers yeast I have heard mentioned.

Any others?

Kevin

[DBA Forum (B) - Charles Mclaren]

The breather should always be 2 inches or more in diameter. This allows oxygen in which prevents the effluent becoming anaerobic. The smell will then be vastly reduced. C

Charlie McLaren...Sent from my iPhone

Post by DBA Forum (B) - Kevin Wade
We have a plastic Vetus 390L black tank. It has a Vetus carbon filter to supposedly refine any air emanating from the tank as it is filled. This has clearly stopped working and the stench is quite vile when the toilet is flushed forcing air out.
Disregarding the carbon filter, what can I do to the tank to "sweeten" the inside up? Brewers yeast I have heard mentioned.
Any others?
Kevin

[DBA Forum (B) - Peter Cawson]

Well I would have thought that the tank should simply be vented overboard. A hose from the tank up to a through-hull fitting beow the deck level would seem a di-stink-t possibility.

Peter

[DBA Forum (B) - Kevin Wade]

The vent tube is 25mm as supplied by Vetus and is vented to the outside rear of the boat. I suspect the problem is exacerbated by the being in the the engine room and so gets warm as the cruising day goes on.

[DBA Forum (B) - Andy Soper]

Hello Kevin,

The Vetus filters cost and arm and a leg and do little.

I removed ours to allow a free flow of vapour - no problems encountered - except when very full!

(Our tanks and vent pipes in engine room)

[DBA Forum (B) - Frank Kordbarlag]

I don´t have a black (or grey) water tank, Where do you empty them anyway? I have yet to find a pumping out facility and I travel all over Europe with my barge.

Frank

[DBA Forum (B) - Chris Green]

Post by DBA Forum (B) - Peter Cawson
Well I would have thought that the tank should simply be vented overboard.
A hose from the tank up to a through-hull fitting beow the deck level would
seem a di-stink-t possibility.

Standard on houses of course, it's required to have access to open air
to prevent air locks in the pipes down to the sewers. It's called a
'soil vent' in the UK. You see them running up from the soil pipe
running down the sides of houses, they usually stop around gutter
level and have a bit of net over the top to stop birds getting in.

[DBA Forum (B) - Charlie Hayden]

As regards the smell, I notice no one has mentioned adding a toilet freshened/cleaner like Toilet Duck.
Should these be added to the holding tank to reduce odour.
We have a vent outlet on the hull about 50 cms above the waterline. Recently spiders have decided this is the ideal place to build a nest and rear a family. Strange things these spiders. This nest blocks the vent and the tank builds up a slight positive pressure after a flush. This results in the sensor light indicating a full holding tank.
Took me a while to figure that one out.
Anyhow. What about adding a loo cleaner type liquid to the tank.

Charlie.

[DBA Forum (B) - Roger Millin]

We have recently started using Harpic, Gel Fosses Septiques (Menthe Fraiche) toilet cleaner for our toilet which then goes into our black holding tank. We have a carbon filter system for venting which has been OK for several years now and there is no smell in normal use. However, since using the Harpic product designed for fosses septiques we are pretty sure that the slight smell that we get as our black tank pumps out overboard underwater right at the end (part waste fluid, part air) is less whiffy than with earlier toilet cleaners. I presume that the product, designed not to kill the bacteria in fosses septiques, is allowing a better digestion within the tank. The product claims to clean, descale and perfume and we believe that it does just that. It also says that it is an organic biodeg
radable formula. We find it commonly available in French supermarkets. We believe that it works but I am sure that there will be others that pooh pooh the idea. Pun intended.
Roger