Yes, it would be a best practice. I replaced all of the “above-water” thru hulls, and many are “barely”. Under motor, the cockpit scupper drains are definitely below the water line. But sitting in the slip, they are above.
Man, you need to make sure you never travel outside your protective cocoon. A LARGE part of the world has those signs in every toilet everywhere. And a LARGE part of the world provides a trashcan for the used toilet paper. Like a boat, they are all plumbed with 1.5" PVC, with no easy way to unclog them other than to rip out the plumbing like needed on a boat.
No psych exams needed. It was only a few decades ago that all marine toilets were manual toilets. But then the marine industry began marketing to everyone with a pulse, most of whom didn't really want a BOAT, they wanted a floating condo...and most new boat owners still do. Toilets "like the one at home"....entertainment centers, central heat and air....microwaves...
You were doing pretty well till you said that. Fresh water DOES keep the toilet discharge line cleaner and reduces sea water mineral build up in it and the rest of the sanitation plumbing, but there's so much bacteria in sewage that whether you flush with sea water for fresh makes no difference in the holding tank., but oxygen does. Bio-physics 101: when organic matter breaks down in AEROBIC (oxygenated) conditions, it converts to CO2, which is odorless. It's when it breaks down in ANAEROBIC (without oxygen) that it generates hydrogen sulfide and sulfur dioxide gasses (stinky ones) and methane, which is odorless but flammable.
A question if I may ................. do you advocate for full fresh water flushing all the time OR salt water flushing followed by a fresh water rinse ? Both will accomplish the same thing if the rinse hose enters the raw water hose at the sea water inlet thru-hull.
Thanks @Peggie Hall HeadMistress for interjecting that fact and straightening out the poster's #8 remark. I wasn't entering that disjointed mele for anything.
Yes all joking aside, that is the most likely reason for fresh water flushing as opposed to sea water flushing followed by fresh water rinsing.
If I may offer, a valve could be added just past the "T" takeoff to the head and this would allow fresh water (from the sink) to enter the head for a final rinse before leaving the boat.
Yes, keeping an aerobic tank helps to eliminate odors. But few, and I mean few, boats can keep their tanks aerobic enough because of build and design constraints. The fact is that fresh water over salt water helps in this situation by reducing calcium carbonate buildup in the tanks (and that smell is not helped by aerobic conditions), and it dissolves waste products easier than salt water, which allows them to go aerobic quicker. This is the physics of it.
Edit. Not to put too fine a point on this, but I just did some searching on the bacterial species responsible for both aerobic and anaerobic breakdowns of waste in holding tanks. I have a background in microbiology and chemistry, so this interested me. In all cases of aerobic bacteria, salt water significantly attenuates their growth and survival. E. coli, for example, has a 92% death rate in salt water, and Pseudomonas aeruginosa is similar, although a bit more tolerant. Meanwhile, anaerobic species like Prevotella thrive in salt water, although Bacteroides can be attenuated. The anaerobic bacteria outcompete aerobic bacteria in salt water, while they do not in fresh water.
Any thoughts on the difference between living aboard vs. occasional use? Any differences in pump out frequency? Any differences in the amount of oxygen being added to the tank via flushing frequency? Was this the same boat in each place, or different boats? Was salt/fresh water the only difference?
That product contains calcium nitrate as its active ingredient. Calcium nitrate doe not enrich the oxygen supply in the waste water. Instead, anaerobic bacteria will preferentially metabolize it instead of sulfide compounds, so the production of hydrogen sulfide is reduced. It does nothing to increase the aerobic conditions of the tank, and in fact promotes anaerobic bacteria by providing them with easier food (but it does help them not stink as much) The downside is the production of nitrates is increased, but at holding tank levels, this isn't as much of an environmental concern.
Odor from flush water in the bowl is much less with frequent use. Nonexistent in fresh water, unless the harbor water is polluted.
Not sure where you are getting your information. The main ingredient, about 70% is ordinary salt. The second ingredient is Sodium Carbonate Peroxyhydrate. There is some coloring and fragrance.
Yes, you are correct, thanks. It seems that the company has a "TST Max Orange" product, and a "TST Orange" product. I had looked at the SDS for the latter.
What I was asking is if your experience that fresh water caused more odor than salt water might be due to how the boat was used? Maybe living aboard in salt water has you flushing more frequently (higher exchange of oxygen), and pumping out more frequently (less time sitting anaerobically)? These factors are not salt/fresh dependent wrt odors. Also, it wasn't clear if this was the same boat, as different boats might have different waste plumbing designs. Boat waste systems are often notoriously bad designs from the factory.
I don't know where he gets it either, Dave. And thanks for being our fact checker. I would think that anyone who claims a background in chemistry would recognize "Peroxy" as an oxidizer.
...............which was then reinforced with :
For God's sake man, you screwed up. No one is interested. No one cares.
Are you OK? You seem to have easily triggered issues that are outside the norm in general, and this forum in particular.
