Making Water in Harbor?

[Adelie]

When you engage in speech in the public realm you will encounter plenty of folks with strongly held beliefs on all sides that are willing to energetically argue them.

While CF is not exactly the public sphere, it’s at least adjacent to it.

[waterman46]

I have been tempted to use the watermaker in non-commercial harbors which have visibly very clean water. I told my wife that this thing filters out salt molecules which are way way smaller than poop molecules, even smaller than viruses. But she insists we do not use the watermaker unless more than 3 miles offshore.

I always worry about a tiny hole in the membrane so I agree with her. You could get low TDS readings and still have a few bad actors in that water if you are taking it from somewhere near town or other boats.

The issue is not how long you can run w/o changing filters. There is an actual health issue. By only using it offshore, this keeps the prefiliters so clean I can use them for months with flushing them out after each use.

[rslifkin]

If you're concerned about bacteria, etc. that might have made it through despite a good TDS reading, you could run the water through a UV sterilizer to make sure there's really nothing living in there.

[mikedefieslife]

Sewage is non-issue for watermakers, not that you will find much of it in the waters of most EU countries.

The dock water where I am now is measuring 115ppm compared to my watermaker Eco-sistems Splash 25) that has pressure issues at 850ppm.

The dock water is cheap here too at around 6c/l

In the Med you could easily pay €25-30 a time getting water. Especial in Sicily, Ibiza, and Corsica.

[captlloyd]

Originally Posted by boat_alexandra

so you freely admit you discharge oil? This is prohibited, and I have never done it.


I have found a way to bring it to the point of not leaving a sheen. You don't have an engine in the boat. When are you going to pay up for the real cost of your engine?

Then you don’t have a gasoline powered boat or dingy. Your fantasy world must be beautiful.

[Lepke]

I'm going on 10 years of nothing but watermaker water. I have the water tested occasionally, tests much better than city water. I winter in fresh water cruise in salt but before shutting down my watermaker, I flush with fresh. I have more filters for silty conditions. I use water like in a house, dishwasher, washer, etc. Membranes going on 10 years.

[barnakiel]

Originally Posted by mikedefieslife

Sewage is non-issue for watermakers, not that you will find much of it in the waters of most EU countries.


(...)

Hey hey hey. Greeting from Spain.


A sewage outlet in nearly every marina.



Maybe you meant most Nordic EU countries?


barnakiel
Las Palmas, Canary Islands, Spain

[Manateeman]

Reverse osmosis is a great technology. It does not remove all things dangerous from seawater. I have an large RO and offshore, it makes very high purity water.
The OP asked about inshore. Even in a harbor, RO will function if...and it’s a big IF, the membranes are well maintained. It will remove bacteria, virus particles and will even work if you feel the need to anchor in a nuclear power plant water discharge. There are chemicals which it will not remove no matter where you run your water maker. Not my opinion, just the science.
Some of these chemicals are carcinogenic, some endocrine disrupters.
That is why I said in my prior post not to worry about the membranes in the RO unit, worry about the membranes in your body.
I’m not going to delineate the science on these chemicals nor the science of what happens to your membranes when you drink water containing these persistent toxins. Go read PubMed on your own or pay your Physician a visit.
Let’s take boatbuilding stuff. MEK. Nasty. Ok let’s garden. Herbicides, fungicides.
How about a dash of Methanol or Acetonitrile. Lots of nice solvents too.
In the Aptly named the Cape Fear River, you’ll find a mix of 30 types of PFAS chemicals including the ever popular local, GenX. Perfluroalkyl and Polyfluoroalkyl pass through RO membranes. You can save time by eating some of the fish or shellfish from my home town harbor New Bedford which has lots of PCB .
Better living through chemistry. The manatees are smiling at the woman who told her husband , three miles out. Easy to remember. Three mile island.
Happy trails to her.
Mark, not a Love Canal manatee

[MicHughV]

use tank (ie, tap water) for washing the dishes
use bottled water to make the coffee...
use beer for drinking....

[zboss]

Its not the membrane you have to worry about because those are fairly cheap to replace. Its the scoring of the high pressure components from the dirty water. Even water that's gone through a 5 micron allows some not insignificant percent of sediment above 5 microns. For example:

https://www.home-water-purifiers-and.../pentek-ep.php

[Jerry Woodward]

I made water every 4 days for about a month in Boot Key Harbor with my Cruise RO watermaker. Great tasting water. No problems.

Rich Boren of Cruise RO has a good video with a practical common sense discussion of the issue:
https://www.youtube.com/watch?time_c...ature=emb_logo

[LittleWing77]

Originally Posted by sailorbobdeb

Wow, just wow!!! No wonder lots of people hesitate to post . . .

Okay, everybody, just back off on boat_alexandra.

For those of you who don't know him, he is a circumnavigator and a VERY strong proponent for the environment and environmental sustainability.

He sails on a boat with no engine and uses a sculling oar for close-quarters manoeuvring.

He provides a valuable perspective on this Forum and for those who wonder if it could be done? - He's done it.

A little respect, please!
LittleWing77

[Manateeman]

Anecdotal accounts are not science. Period. They are not necessarily true nor reliable. Empirical evidence is measured, unbiased and reproducible. A story verses a set of reproduced facts. Let’s begin with measure. On oceanographic vessels there are scientists who have spent a lifetime studying the sea, life in the sea and the sea bottom. Samples of sea water are routinely taken back to a laboratory because even on the most well equipped vessels, testing accuracy and reproducibility on a vessel cannot attain that of a larger land based lab. What I just wrote is anecdotal because I did not reference a respected journal. I told you a story. It’s not necessarily true and it might not be false but it is not science. It’s not empirical evidence.
Let’s say I run my RO in the Cape Fear River. The water looks fine, smells fine.
I drink it and I don’t feel sick. All anecdotal. And it would be the same if I did this in North Cape Norway. So I’m saying there is no safe RO water anywhere ?
No. And by the way this is a classic false reductio ad absurdism argument.
Your nose and tongue are not laboratory devices.
In any major city, you can find a public water quality laboratory. In it, are people trained to find bad stuff in the water. They have expensive equipment. They take thousands of samples. They know three things. One. RO is an excellent technology. Two. It does NOT remove all the bad stuff. Three, anecdotal stories are not empirical evidence and can lead to dangerous conclusions.
The science of RO is well established. 1. You need good equipment and it must be well maintained. 2. The better the quality of the water going into this equipment, the better the quality of the water produced. A seperate but equally important science, oceanography, tells us that in general, the further away from man made pollution, the less, persistent toxins will be present. Running your RO offshore is safer than running it in any harbor. I’m not an expert in oceanography. I have testified as an expert witness before the U. S. Senate Committee on Science and Technology so I believe I have a reasonable understanding of the facts.
Again, my compliments to the woman who runs her RO three miles offshore.
Happy trails to you.
Mark, no three mile island manatee

[Chotu]

Mr Manatee:

I'm confused as to how a membrane that can keep salt out will still allow large, organic molecules like PCBs or MEK through.

Can you explain?

A quick Google yields the following:

"The pore size of RO membrane is 0.0001 microns which is smaller than the size of the Sodium Chloride Molecule which is 0.0007 micron and will not let it through."

PCBs look something like conjoined benzene rings. (See attached image) Typical huge organic chemistry molecule.

These are significantly bigger than NaCl which is filtered out by the membrane.

[Tellie]

Watermakers= Offshore pieces of equipment. Don't ask for trouble.