Holding tank, how to keep the tank fresh

[simonfraser]

I rinse the heads out v well after use & with fresh water before leaving the boat on the trailer
the outlet was open last week, on the trailer, bit of a pong, summer time
could just close the outlet when ashore, there is no tank bypass valve
i use nappysan to clean out the heads, possibly use more to sort the tank out ?
or ?

 

[Chiara’s slave]

I find, after many years of experience, that no matter what I do, my 5h1t still stinks. There seems to be nothing I can do about it, despite the entreaties of Chiara’s owner.

 

[neil_s]

I use Elsan Blue - but in the hot weather, you still need double measure to keep the pong down.

 

[Chiara’s slave]

I use Elsan Blue - but in the hot weather, you still need double measure to keep the pong down.

You can’t then pump it over the side.

 

[MoodySabre]

Mine has a vent via a charcoal filter. No smell.

 

[Bilgediver]

Mine has a vent via a charcoal filter. No smell.

That does work for some instead of Blue which covers the smell is an enzyme / bacteria treatment and in the UK we have Odorlos. Some marina chandlers do stock it and probably have no idea what it is for.
If you want to do it in another way then fit two breather pipes on opposite sides of the boat 1 " bore and this will get the oxygen in as it doesn't flow in via a single small bore pipe.

Odorlos in one of the few products The Headmistress has endorsed so should do the job.

Odourlos Holding Tank Odour Treatment (1 Litre Bottle)

 

[simonfraser]

Cors I have a vent hole and a drain hole …
tnx for all you comments, as said only smells when 30C

 

[Bilgediver]

Cors I have a vent hole and a drain hole …
tnx for all you comments, as said only smells when 30C

You are lucky . I believe Odorlos was formulated in Norway where the temperature rarely reaches 30C . Many people have found it does work.

 

[Momac]

I previously used Elsan Blue until I found it is highly toxic.

To be sure of flushing out the blue stuff I used no chemicals for a season. I then started using Odourlos .

I have been very pleased with Odourlos. It seems very economical . The dose after first use following tank pump out seems to do the trick.

 

[westernman]

Mine has a vent via a charcoal filter. No smell.

Same here. And no smell when it is 38C outside either.
The key thing is the vent to allow the proper bacterial reactions to take place.

When I empty the holding tank at sea, I just flush it through with plenty of sea water. Nothing else added.

If it smells , then something is wrong. Probably a blocked vent.