Why do so many Heads have that Musty Smell?

[djtopper]

Ok, great. At least from my perspective as a relative noob here, I'm glad to see there are some potential workarounds. I figured there were. I may even try some on a charter if it suffers from "the stank" effect.

[Rakuflames]

Originally Posted by David M

The smell is from dead plankton, but as you say it could also be contamination from actual poop. But in the absence of human waste, the smell can be purely from plankton.

The clearer a body of water, the less plankton that is found in the water. Very clear fresh water lakes will not cause much stink at all if any. Rivers and estuaries that are loaded with nutrients that allow for intermediate to large amounts of plankton will cause the head to stink when the plankton dies. The primary indicator as to how much stink there is going to be is water turbidity. Yes, that sulphury smell is an indicator of anaerobic conditions.

I do this kind of stuff for a living. We study water chemisty, nutrients and plankton....this part of the food web. Anyone who has kept nutrient loaded water in a closed container for a few days regardless of salinity and then opens the lid and smells it knows how much it smells like sulphury poop.

Given your background there's something I've wondered about for a couple of years. Two summers ago we had a SPECTACULAR display of bioluminescence, but particularly in the marina I was living in, where it was so active and bright that in a movie you would have assumed it had been done by computer.

I always wondered what was in that marina water that caused such an intense bloom -- an electric aqua that splashed several feet into the air sometimes.

Do you know what that algae feeds on (I can take it, and I resisted jumping in to play in it because of that question ...)

[TeddyDiver]

Originally Posted by djtopper

And why would a Lavac toilet help?

Bcs the the waste is removed before the flush. Normal toilet blends them and further flushing just dillutes it some more. To get same result as Lavac with one you need a dozen flushes.. Lavac Marine Toilets

[delmarrey]

Originally Posted by Rakuflames

I guess I'm just lucky -- mine doesn't smell. I wouldn't be able to stand that sewer/urine smell and I'm not fond of mildew either although it's easier to deal with. It is possible to eliminate the smells, and really worth the effort.

I must be lucky too! My boat is 32+ years and no smell, sewage or diesel. It all comes down to maintenance and securing leaks. I wouldn't own a boat that smells!

[djtopper]

Originally Posted by Rakuflames

Given your background there's something I've wondered about for a couple of years. Two summers ago we had a SPECTACULAR display of bioluminescence, but particularly in the marina I was living in, where it was so active and bright that in a movie you would have assumed it had been done by computer.

I always wondered what was in that marina water that caused such an intense bloom -- an electric aqua that splashed several feet into the air sometimes.

Do you know what that algae feeds on (I can take it, and I resisted jumping in to play in it because of that question ...)

I'm gonna guess fertilizer runoff from nearby lawns and gardens. But that's a wild guess from someone who does not deal with this stuff on a daily or professional basis.

[thinwater]

Originally Posted by djtopper

I'm gonna guess fertilizer runoff from nearby lawns and gardens. But that's a wild guess from someone who does not deal with this stuff on a daily or professional basis.

And those that flush at dockside.

And the tremendous amount of surface area for growth (particularly floating docks) add.

[rivonia]

The smell is nothing to do with dead micro organisms. It is caused by the uric Acid (urine) mixing with salt water- simple and basic as that. If the heads are pumped correctly SEVEN pumps per meter, you will not have any smell. Our heads and holding do not smell and never have. If there is a smell, it is bad management.

[delmarrey]

Originally Posted by rivonia

The smell is nothing to do with dead micro organisms. It is caused by the uric Acid (urine) mixing with salt water- simple and basic as that. If the heads are pumped correctly SEVEN pumps per meter, you will not have any smell. Our heads and holding do not smell and never have. If there is a smell, it is bad management.

I disagree.
The urinal's on navy ships that I've been on, over the years, would start building up salt crystals from the urine and they didn't smell, unless you stuck you face into one.

Just take some harbor sea water and seal it up in a jar and put it in a dark place for a couple weeks. Then open it up. You'll love the smell.

[Rakuflames]

Originally Posted by djtopper

I'm gonna guess fertilizer runoff from nearby lawns and gardens. But that's a wild guess from someone who does not deal with this stuff on a daily or professional basis.

Very little "lawn and garden" near that marina, so I really don't think that explains it. I always suspected someone was dumping their head overboard just from odors that wafted around from time to time, and I wondered if that could be it -- and it was enough to keep me out of the water! But I'd love to hear what our resident specialist says about it.

[clockwork orange]

The idea of fresh water flushing (unless on a lake) to me is impractical. On a small boat you just don't carry enough, even flushing with 7 pumps of seawater as has been suggested would fill my small 14 gal holding tank way too soon with mostly water requiring pumpout. Has anyone figured out how much water it takes to do an adequate flush?

Steve.

[Steve Bean]

The amount needed probably varies depending on the plumbing of each boat. With a composting head, it's approximately zero ounces. That's also the number of through-hulls needed.

[Rakuflames]

Originally Posted by clockwork orange

The idea of fresh water flushing (unless on a lake) to me is impractical. On a small boat you just don't carry enough, even flushing with 7 pumps of seawater as has been suggested would fill my small 14 gal holding tank way too soon with mostly water requiring pumpout. Has anyone figured out how much water it takes to do an adequate flush?

Steve.

I'm a coastal cruiser with a coastal cruiser boat, so I have small water and head tanks also. We carry extra water in five gallon camping water bags. We ... er ... don't flush with every use, but flush with 2 gals. when we do. Go three miles off shore, and you can legally discharge. Or you can pull into a marina and both get more water and a pump out.

You can flush with salt water for periods of time without odor, but eventually you will have an odor. One option then is to pull in somewhere, pump out, and then flush your system well with fresh water and pump out again. When I had a salt-water based odor problem, I did not find any additives that solved the problem.

[delmarrey]

Originally Posted by clockwork orange

The idea of fresh water flushing (unless on a lake) to me is impractical. On a small boat you just don't carry enough, even flushing with 7 pumps of seawater as has been suggested would fill my small 14 gal holding tank way too soon with mostly water requiring pumpout. Has anyone figured out how much water it takes to do an adequate flush?

Steve.

You only need fresh water if it's going to sit for awhile, unused. Just use a 5 gl bucket and pour in what you can and dry flush, then the rest and dry flush. If it's City water it'll have a little bleach in it already to help keep down any micro growth. If not City, then I'd add a teaspoon of bleach to the bucket.

If possible, it would be good to back flush the inlet line too.

On my boat I have even setup a fresh water flush for my motor & galley sink, also the anchor washdown system, which is connected to the head inlet. Two birds with one stone in two different locations.

[rivonia]

Here are some facts The reason it happens. What actualy happens is that bacterial action on NITROGEOUS compounds in URINE produces AMONIA. TheAmonia raises the PH at raised PH CALCIUM and MAGNESIUM, previously in solution as BIOCARBINATE are deposited as insoluble CARBONATES-Sea Water has high tempory hardness due to the disolvedBiocarb.

[Caracal]

Originally Posted by rivonia

Here are some facts The reason it happens. What actualy happens is that bacterial action on NITROGEOUS compounds in URINE produces AMONIA. TheAmonia raises the PH at raised PH CALCIUM and MAGNESIUM, previously in solution as BIOCARBINATE are deposited as insoluble CARBONATES-Sea Water has high tempory hardness due to the disolvedBiocarb.

Throw in some sort of anode to lower the PH value?

I always thought that the "crust", for want of a better word was ordinary concretion like what happens in water with a lot of minerals (and your bathtub and taps/faucets).