Anyone used an under sink reverse osmosis unit to purify water FROM FRESHWATER tank

[lordgeoff]

We run our water maker weekly during the cruising season and pickle over winter. We keep the Desal water separate from the four main water tanks as they get varying quality of Marina/Town Dock water from time to time.
If you want to be fussy, as I said earlier, just install a domestic charcoal filter just before your tap to take away any perceived or actual unpleasant tast of Marina water. RO before a tap on your boat? Wll probably get screwed by the chlorine in most/all marina water.
In the Med bottled water is cheap. €0.20 for 2Lt. Carrying it back to the boat is a pain.
For total safety? Drink beer from a sealed container. 500ml bottles, chilled are the safest....

[barnakiel]

Originally Posted by Jsta_Rebel

(...)

.. I'm just some guy that makes a living designing and installing industrial Desalination plants throughout the Caribbean for islands, top resorts, and marinas. BTW to the guys that say most marina water is lousy. Most have their own desalination plants ALL IGY marinas do worldwide.

(...)

IGY might, but it is a small world as looking at their website I can see maybe a dozen of marinas spread thru the US and Caribbean. This is hardly worldwide.

Yes, there is a bigger, wilder world behind this backyard.

WORLDWIDE marinas do not have their own desalination plants: not in Auckland, not in Cape Town and not in Papeete.

And cruiser's water can come not just from tap but also from rain collecting systems (e.g. in Nukualofa) or right from a river or a creek (e.g. in NC).

So, my point is you are 100% right, in your backyard. When the water in the tank is from a desalination facility, it does not need any further treatment.

Then when it comes from a rain tank or a river, the better one can filter out the bad stuff, the better for one's health.

So I am still of the opinion that a house standard RO under the tap may have a benefit for some cruisers (e.g. those that venture far and out in boats that do not carry a salt water grade RO system).

Sail and stay healthy,
Love,
b.

[CdS2 Roland]

Hello,
Running a reverse osmosis watermakerwith freshwater will damage membranes definitively. Freshwater can only pass thru membranes without pressure.

[botanybay]

Originally Posted by Jsta_Rebel

I'm thinking you want to insure as much as is possible that you have quality drinking water from your taps. First, when the water tank is very low on water, add a good amount of bleach (1 cup) to it and starting at the faucet furthest away, run it until you smell the bleach. (wont take long). then do the same to the other faucets and taps. Then run the remainder through the hot water side (if you have it) and completely drain your tank. Let sit overnight and flush either with freshly loaded water in the tanks, or preferably from a shore water connection. This will sanitize your boats entire water system. I'd install a 10" carbon block filter 5 micron after the FW pump so all water goes through it that enters the boats water lines and then add a very little amount of bleach (cap full) to the FW tank every time you fill it. Buy yourself a cheap little pool test kit to check the chlorine with if you want and keep it at 1 ppm free chlorine. on just the line feeding say your kitchen sink, you could install a small silver impregnated ceramic filter or even another carbon block with a 0.5 micron rating that would give you very high quality water for drinking.

Remember, I AM NOT trying to use a salt water RO unit for this purpose. It is amazing how many comments are in this list which did not read the original post...

Guys, I am just trying to avoid crew bringing the most useless and environmentally damaging thing in the world aboard... Bottled Water...

I happily drink the water from my tanks, they are spotless, I run a biocide solution used for making beer through the system once a year, all of the piping is clean, as far as I am concerned life is good.

I have used a britta pitcher, have one sitting on the counter right now. However, at sea for extended periods of time they are a pain in the neck.

The main tanks are 400 gallons so I suspect returning reject water to the tank is unlikely to have a significant impact on TDS but I could see it might be a problem when the tank is nearly empty.

I did look at the "no waste" system which was suggested. It turns out that it feeds the reject water back into the hot water system keeping the entire system at pressure. I suspect it is assuming a larger tank than we use on boats to ensure that the TDS does not rise in that part of the system. It also assumes you can back feed the hot water tank (i.e. no check valve) and I don't know if that would work using a mixing valve at the hot water heater.

Just an interesting thought for great tasting water aboard...

[botanybay]

Originally Posted by Dave22q

I want to be kind but... Unless you make a practice of filling your tanks with swamp or sewer water this idea is absurd. Talk about solutions to non problems. BTW whatever gave you the idea that bottled water is superior to tap water (at least here in the US excepting Flint Mi)?

The general issue is crew who keep wanting "Bottled Water"... I have used a two stage carbon filter on a second tap for years on the previous boat and it was a wonderful addition. There are many parts of the US with perfectly safe water to which I don't care for the taste.

[botanybay]

Originally Posted by barnakiel

Your idea is not silly and I think you should make a deeper research maybe then prototype some and see what happens.

Never listen to people who never did this but will tell others this or that can't be done. Like Hillary would never have climbed THE mountain.

I have seen a small RO brackish water unit employed on a big maxi size yacht. One of the big players. It was in the bay under the sink. Unit made in Catalunya sized for off the grid weekend households (finkas=huts) with brackish wells. I cannot tell you how it was wired but the tap of it exited just next to the fresh water tap in the galley. Clearly this water was then used in the kitchen. (?)

Do you want me to look up that installation to see how this RO unit is wired into the (many) tanks? I have seen such units in local shops.

Another clue: In Sweden they have showers that cycle shower water in real time. Not sure what process they use, perhaps low pressure RO or light or a combo.

Cheers,
barnakiel

Thank you for the feedback, I have spent quite a bit of time in Sweden and really love the place! I would be curious how they were plumbed into the system...

If the TDS of the main water was to become a problem (which I doubt with a 400 gallon tank), I could pull water from the reserve tank and dump the reject into the main tank which is mostly used for showers, dish washing, clothes washing and the like.

However, as some have said, keep it simple... With a 400 gallon tank I really doubt that making a few gallons of RO drinking water for a separate tap is going to make any significant impact on the TDS of the main water tank.

I would definitely be interested in how those kinkas are plumbed up, I am just trying to not dump the reject water down the drain to conserve water.

Thank you very much for the feedback!

[botanybay]

Originally Posted by McKenna

I have used the Watts Premier reverse osmosis zero waste unit for years. The unit is about $388 not difficult to install or maintain. Filter cartridges replacements are inexpensive. You have an excellent idea stick with it for you and your crews health.

Thank you for the pointer! Looks like an interesting system, did some research and it appears to be pushing the reject water back into the hot water line and backfeeding the hot water tank.

It does note that there must be enough length of line between the hot water heater and the unit. Perhaps to avoid the water coming into the unit becoming too hot... Interesting concept as the hot water is nominally used for washing and the like and so assuming a 2x reject rate a 2 gallon tank would pass back something like 4 gallons of water during a fill. Might not be significant...

Not sure if there is any significant benefit over just dumping the reject water back into the water tank though. More of a benefit to a system which does not have a tank and pump (i.e. home systems).

The literature does note that an average dump system will reject some 7000 gallons/year of water which seems like a lot...

Thanks again for the pointer!

[botanybay]

Originally Posted by CdS2 Roland

Hello,
Running a reverse osmosis watermakerwith freshwater will damage membranes definitively. Freshwater can only pass thru membranes without pressure.

As the original post, that is not what I am talking about, I am talking about using a system designed to take household freshwater and make a supply of RO water available for drinking water and the like.

[SeaSon]

I can definitely state my ice is crystal, and I mean crystal, clear.

Sent from my SAMSUNG-SGH-I537 using Cruisers Sailing Forum mobile app

[valhalla360]

Originally Posted by Dave22q

I want to be kind but... Unless you make a practice of filling your tanks with swamp or sewer water this idea is absurd. Talk about solutions to non problems. BTW whatever gave you the idea that bottled water is superior to tap water (at least here in the US excepting Flint Mi)?

Agreed, the vast majority of bottled water is just tap water put in a bottle.

It depends on where you are cruising but if the fresh water source is that questionable, just get a full RO unit and make your water from seawater. In most parts of the world, city water is perfectly healthy to drink.

If it's a flavor/odor issues (safe just not desirable), a charcoal filter will take care of it without the complications.

Montezuma's revenge is 95% of the time just exposure to a new set of germs. That's why the locals can drink the water with no problem. You will get exposed to those germs if you stay in the area even if you drink RO water. Given a week or two, it's a non-issue.

I also suspect that just like using too much anti-bacterial soap, your body atrophies and you will be more susceptible in the future because it loses it's ability to handle germs.

[ErikFinn]

I want to take this opportunity and ask the cruisers in Asia if they drink the tap water (marina city water) unboiled and untreated in developing Asian contries? While I realize not all countries are the same and I trust tap water in countries like Japan and Korea should be perfectly ok, but how do people find the tap water in countries like Malaysia, Thailand, Philippines, India?
I have dranken the local tap water in malaysia and I reckon it is ok, but I always have a thought in the back of my mind if something is not right.. Not to mention a few weeks ago I bought a 1.5L bottle of drinking water from a supermarket and that taste just wasn't like it should have been. But I drank it anyway.
I have heard the tap water in Vietnam, Cambodia, Laos, Myanmar is not drinkable but I don't know the facts.
How do you determine if you will drink the tap water in a new country? Do you just google it? Ask locals? Never drink it? What do you do?
Cheers.

[dtboats]

I thought I would take a moment and let you know that I have used for a little over a year a product made by Perfect Water Technologies. I installed the Home Master Hydroperfection Reverse Osmosis Water Filtration System and have been thrilled with the results. The install is on a 30 year old aluminum boat. I check the TDS every month and the last test showed 270 ppm which is well below the maximum acceptable of 500 ppm. The unit has been online now for one year and we live aboard. I ordered a complete filter and UV light replacement kit for $130.00 to complete the annual recommended maintenance and will be installing next week. Instead of using bottled water we use the dedicated spigot for filling our drinking cups and making coffee. So far so good. For the record I have no affiliation whatsoever with this company. Just a very happy customer. Good luck!

[botanybay]

Originally Posted by dtboats

I thought I would take a moment and let you know that I have used for a little over a year a product made by Perfect Water Technologies. I installed the Home Master Hydroperfection Reverse Osmosis Water Filtration System and have been thrilled with the results. The install is on a 30 year old aluminum boat. I check the TDS every month and the last test showed 270 ppm which is well below the maximum acceptable of 500 ppm. The unit has been online now for one year and we live aboard. I ordered a complete filter and UV light replacement kit for $130.00 to complete the annual recommended maintenance and will be installing next week. Instead of using bottled water we use the dedicated spigot for filling our drinking cups and making coffee. So far so good. For the record I have no affiliation whatsoever with this company. Just a very happy customer. Good luck!

Interesting unit. Although it shows that only the highest end unit removes biological. I don't understand that as they should not pass through the standard membrane.

[nigelmercier]

Why not just buy bottled water? This has the advantage that you can keep it in the refrigerator.

[barnakiel]

Originally Posted by nigelmercier

Why not just buy bottled water? This has the advantage that you can keep it in the refrigerator.

Nigel,

Bottled water is not universally available. You may be simply in an area where such water is a luxury or where there are simply no shops, etc.

With water it is often belt and braces for boats that go to the off the piste places.

BTW the other liquid, the one you are sipping on your avatar ... an even better solution than bottled water!

;-)

b.