Fresh Water or Salt Water to flush the toilet?

[windlass79]

A friend mentioned that they used fresh water to flush the toilet on their boat. He believes it helps to reduce the odor coming from the holding tank.

I'm curious do you use fresh water or salt water to flush?

Cheers,
Rob

[GordMay]

I used fresh water, when dockside, and prior to any temporary disuse (leaving the boat for more than a day or two).

[Woodland Hills]

Saltwater is full of plants and animals, they are usually too small to see with the naked eye, but once they die in the toilet bowl you sure can smell them! A freshwater flush avoids this completely.

[Sailmonkey]

We use fresh from the vanity sink drain while at the dock with a hose that delivers free fresh water.

But out cruising and living on the hook we use salt exclusively.

The water isn’t usually in the hose Long enough to smell, nor is the holding tank filled long enough to stink.

[Freedom45]

We use fresh only.
Yes, one might have less odor but more important to me is no build up that develops in the discharge hoses and holding tank.

[LoudMusic]

We have a water maker so we use fresh water always. If we had limited fresh water supply I might consider sea water flush.

[sailorboy1]

I don't feel it makes any difference at all which water you use far as the odor going out the holding vent.

But it makes a big difference on the odor coming from the head itself while flushing due to the dead stuff in the flush water loop.

So in a marina I use fresh water because I have it. When not I don't.

BTW - less hose scale etc. also when using fresh water

[Scubaseas]

Fresh water is fine for zero head smell but I would not want to hook your fresh drinking water tank to the head. Even with double check valves. Better to use the shower head to fill the toilet bowl. If you use the head every day or all the time it makes little difference other than salt builds scale faster in the hoses. Odor is about the same as long as the salt doesn't sit in the bowl/hoses for a long time.

[a64pilot]

We use fresh exclusively. As we have a water maker.
It would be easy to use salt, but would require a bucket or something to get the salt water into the head, so if our cruising and the water maker breaks, you just flush with a bucket.
Everything about the head is cleaner and easier to service, requires less maintenance etc when fresh water is used.
I got two years out of our last Joker valve and we are full time.
There are specific heads that are made to hook up to your fresh water system and are as safe as the ones in houses, that are also hooked into the drinking water system, just don’t jury rig something yourself, that is how you may get sick.

[thinwater]

Originally Posted by Woodland Hills

Saltwater is full of plants and animals, they are usually too small to see with the naked eye, but once they die in the toilet bowl you sure can smell them! A freshwater flush avoids this completely.

This is a common misunderstanding of the effect. Freshwater (lakes) has critters too, but they don't stink much.

The reason is sulfate. Seawater contains lots and bacteria convert it to sulfide in the absence of air. This happens in the feed pipe and in the holding tank. Freshwater contains far less sulfate.

But yes, dying critters is a problem too. It is good to flush with fresh before leaving the boat for a few days.


And scaling is less. I use fresh anytime I have enough.

[FULLCIRCLE331]

For me fresh water definitely makes a difference. I added an 11 gal bladder for fresh water. If it runs out I can switch to salt water or use the shower head. Reduces odor and salt build up in lines.

[tarian]

The Calcium Problem
Everyone who owns a boat with a seawater toilet knows about The Calcium Scale Problem. Urine mixes with saltwater in the plumbing system and produces calcium scale that builds up in the lines

[a64pilot]

I believe freshwater here is meaning from your water tank.

You do get calcium scaling even with fresh water, I believe it’s lessened, but it still exists.
Interestingly I have never seen a build up in our boat even when it was salt water, I changed the old lines as they were permeated and they were clear.
I suspicion it has to do with how much water was being flushed though, trying to save water or not fill up the tank too fast will I believe accelerate the calcium build up.

We fill our 35 gl tank in four or five days, many think we are crazy, they brag they can go weeks, but I believe they are also the ones with permeated lines that are calcium scale clogged too.

[ToneyFoster]

Fresh. Less ordor and the toilet parts last longer.

[a64pilot]

This is a Raritan Sea Era Joker valve that is two years old, always fresh water and we full time.
Something built up on it, I’m not sure what, I assume calcium, but nothing built up on any other part, which was interesting .