Your Solutions to Sea Water Odors in Toilet Intake?

[Hudson Force]

Originally Posted by Pirate999

............ The water and associated organic material in the sea water sit in the intake and decompose. So when you do that first flush, it smells. ...........

I appreciate that this is a good guess, but I doubt that it stands alone as true. It might be a partial answer, but not without other interaction from the head or a factor with the length of intake pumbing. I have less than a liter volume within my intake from the through-hull to the head. I know that I can place a liter of seawater in a closed dark container for a week and not find an obnoxious smell upon opening it. Maybe a hint of decay, but nothing like the odor related to the first flush of leaving the head unused for a week.

I will admit to an event when I had pumped a small fish into my head intake and the lodged carcass caused an odor problem, but the typical density of plankton in seawater is not the singular source of this problem.

[Freedom45]

AAarrggh
a64Pilot and Peggy
This is the schematic for my set-up



I have one manual and one electric pump to evacuate the heads.
The needle valve is to throttle the vacuum bleed off.
The fresh water shut-off valve is next to the y-valve, I close this valve when switch to sea water.

[peghall]

Originally Posted by jannw

Whilst it isn't installed in my yacht, I recall hearing about a clever system which had a reservoir under the hand basin with a Y fitting, one end to the outside, and another to the toilet inlet. That way your hand washing water could be saved and reused to flush or just rinse the loo. It'd be trivial to build in the reservoir with an overflow outside too.

It's a solution I've recommended for years...EXCEPT for using gray water (previously used sink water) to flush the toilet. It's full of soap scum, body oils and various types of dirt that are not good for the toilet pump, along with bacteria that kinda defeats the whole purpose of keeping critters that die, decay and stink out of the intake plumbing.

Unfortunately, it only works on boats that have below-waterline sink disharge thru-hulls, which pretty much limits it to sailboats and is only practical on boats in which the head sink and the toilet are on the same side of the keel.

[Cavalier]

Originally Posted by Freedom45

AAarrggh
a64Pilot and Peggy
This is the schematic for my set-up

<quality illustration>

I have one manual and one electric pump to evacuate the heads.
The needle valve is to throttle the vacuum bleed off.
The fresh water shut-off valve is next to the y-valve, I close this valve when switch to sea water.

Peggy,

I have exactly the same setup with the only difference being that I have a vent line hose running from the top of the cistern tank to a skin fitting (and above-water overboard). This serves the purpose of venting the tank to avoid vacuum, or as an overflow in the unlikely event that the float-valve fails and tank doesn't stop filling. The tank is connected into the toilet-feed system by the usual 3/4" hose which is tee'd into a Y-valve which can be switched to sea-water supply if required. It is extremely unlikely that contamination could come back through the feed pump, up the gravity feed hose from the toilet, into the tank and then into the pressurized connection from the float-valve to the pump. However, in the event that the boat is left unattended for a long duration and the fresh-water pressure feed pump is turned off, then a ball valve between the feed-pump manifold and the cistern tank is closed as shown by Freedom's most excellent illustration.

I typically close the valve, turn off the feed-pump and then flush the toilet (to empty the tank) when leaving the boat. That way, no end of boat motion could cause the float to lift permitting ingress into the fresh-water system.

The parts for the tank can be found in the Sch40 plumbing section of GnomeDepot along with a standard $7 flush-master toilet valve kit. The valve will actually fit into a Sch40 4" PVC tube if care is taken with alignment and placement etc, on the end caps. A Sch40 PVC female inspection adaptor and cap can be purchase in the same section as the pipe.

If you want to get really fancy (with an electric toilet), you can connect a timed 12V relay across the terminals of the feed-pump for the toilet. That way you can set a "normally closed" actuated valve (set in the pressure-feed line from the fresh water system) to open for a set period once the toilet has been flushed to permit refilling of the tank, only to close off again afterwards. However, this adds another possible failure mechanism with no substantial benefit!

[Terra Nova]

Originally Posted by Cavalier

...It is extremely unlikely that contamination could come back through the feed pump, up the gravity feed hose from the toilet, into the tank and then into the pressurized connection from the float-valve to the pump. However, in the event that the boat is left unattended for a long duration and the fresh-water pressure feed pump is turned off, then a ball valve between the feed-pump manifold and the cistern tank is closed as shown by Freedom's most excellent illustration.

I typically close the valve, turn off the feed-pump and then flush the toilet (to empty the tank) when leaving the boat. That way, no end of boat motion could cause the float to lift permitting ingress into the fresh-water system...

Any safety measures that require operator discipline can be expected to fail.

[Cavalier]

Originally Posted by Terra Nova

Any safety measures that require operator discipline can be expected to fail.

..well then as operators of sailing vessels, we're all doomed!

[Enchanter]

We have done something similar to the diagram previously posted with a separate fresh water tank and float valve. Our tank is a bucket with a screw on lid with a water tight gasket. The bucket is above the toilet at any angle of heel short of a knockdown. We put a vent line in the lid. The one difference I think is that we put a vented loop between the toilet pump and the toilet bowl. Our reasoning was that this would act as a second air gap in the system, with the first one being in the float valve itself. We have this installed on both the manual and electric heads and seems to work just fine, although it is a new install.

[a64pilot]

Why not just add a second water tank? That way your completely safe and not using any drinking / washing water for the head?
I think I'll just stick with using the shower head to flush, just isn't that hard to do.

[peghall]

I think y'all have given me all the answers I need, and I do appreciate your help!

Although I've given up spending several hours a day online in various forums, I'm still glad to answer questions and very willing to try to solve problems via email, so feel free to contact me--or refer your friends--any time you think I might be able to help. My email address is an easy one...just put a dot between my first and last names at gmail.

'Twas great spending time with y'all again! Be well, be safe and enjoy fair winds!

[Tampabayfireman]

Ok about a year ago I got fed up with the smell , clogged lines and such. I installed a 6 gal tank and pressure pump to supply two electric flush toilets. I plumbed the fill from the rear bathroom sink. So when rinsing hands it automatically fills the tank for the toilet. Now for the issue of toothpaste and soap it the water. I installed a y valve that turned one way fills the tank and the other diverts the flow overboard. There are times yes it runs low and I just run the sink for a min to refill the flush tank. And if out cruising and short on water. Just fill the sink from a bucket of sea water to fill the tank. No cross contamination No risks of co mingle drinking water. And no smell.