Reverse Osmosis Units

[billS]

A seagoing friend of mine expressed great surprise that narrowboats were not fitted with reverse osmosis units to purify water from the canal for drinking, rather than taking water from a hosepipe every few days.

 

Does anyone know if this is feasible, and if so, why it has not been generally adopted?

[boots]

A seagoing friend of mine expressed great surprise that narrowboats were not fitted with reverse osmosis units to purify water from the canal for drinking, rather than taking water from a hosepipe every few days.

 

Does anyone know if this is feasible, and if so, why it has not been generally adopted?

 

 

Sounds expensive? what is the water quality like?

 

I have no idea about these units but just wonder if this could be the reason?

 

Martin

[carlt]

A seagoing friend of mine expressed great surprise that narrowboats were not fitted with reverse osmosis units to purify water from the canal for drinking, rather than taking water from a hosepipe every few days.

 

Does anyone know if this is feasible, and if so, why it has not been generally adopted?

RO units are extremely power hungry and expensive.

 

The only sea going vessels that I know of, that have them are serious blue water boats, kitted out for long voyages.

 

A roll of hose is a lot cheaper on the wallet and the batteries.

 

Sounds expensive? what is the water quality like?

 

I have no idea about these units but just wonder if this could be the reason?

 

Martin

The water quality is as good as distilled water.

 

Hospitals use them to purify tap water, to make it suitable for renal dialysis.

[mayalld]

A seagoing friend of mine expressed great surprise that narrowboats were not fitted with reverse osmosis units to purify water from the canal for drinking, rather than taking water from a hosepipe every few days.

 

Does anyone know if this is feasible, and if so, why it has not been generally adopted?

 

Because RO units are eye-wateringly expensive to buy and run, and the only reason that you would buy one is that using a hose is impractical on a long voyage away from water sources.

[Nine of Hearts]

The water quality is as good as distilled water.

 

If you're putting it in your batteries or aquarium, then the water quality is as good as distilled.

 

If you're intending to drink it, then the quality is as bad as distilled. It's generally held that if you're going to drink RO water, you should be taking a mineral supplement.

[carlt]

Repeat thread requiring merger, methinks.

[PaddingtonBear]

Starman is the man for this, at a boatshow (Crick?) a few year ago he was noted drinking water direct from the canal via a Seagull Filter. Perhaps that is why he has not been around very much lately

[Naughty Cal]

Starman is the man for this, at a boatshow (Crick?) a few year ago he was noted drinking water direct from the canal via a Seagull Filter. Perhaps that is why he has not been around very much lately

 

I can confirm that drinking water from the canal (accidentally) is not very nice and requires much mouth rinsing afterwards.

[mayalld]

I can confirm that drinking water from the canal (accidentally) is not very nice and requires much mouth rinsing afterwards.

 

So, very like Lager then?

[casper ghost]

A barrowboat came into the yard a few months ago. The chap said he couldn't understand why his drinking water tank, which was integrated in the bow, never took much filling, no matter how much water he seemed to use. It was discovered that canal water had been leaking into the tank, which he had been drinking for ages...

[RLWP]

A barrowboat came into the yard a few months ago. The chap said he couldn't understand why his drinking water tank, which was integrated in the bow, never took much filling, no matter how much water he seemed to use. It was discovered that canal water had been leaking into the tank, which he had been drinking for ages...

 

I've heard the same tale about a Liverpool boat too.

 

Richard

[Naughty Cal]

So, very like Lager then?

 

Depends on the pubs you frequent. The ones we use serve very nice draft Bud and Coors.

[mayalld]

Depends on the pubs you frequent. The ones we use serve very nice draft Bud and Coors.

 

It's still Lager!

[casper ghost]

It's still Lager!

 

What about Belgian Lager, not too bad......

[billS]

Because RO units are eye-wateringly expensive to buy and run, and the only reason that you would buy one is that using a hose is impractical on a long voyage away from water sources.

 

Apparently you can buy a 100gallon per day unit for less than £100 - which doesn't sound too eye watering. No idea about running costs though - but is it not just a pump?

Edited September 17, 2009 by billS

[carlt]

Depends on the pubs you frequent. The ones we use serve very nice draft Bud and Coors.

They still use the same cats.

[blackrose]

Apparently you can buy a 100gallon per day unit for less than £100 - which doesn't sound too eye watering. No idea about running costs though - but is it not just a pump?

 

Why would you want to pay for this unit and then pump and filter canal water when there are drinking water quality water points around which you are already paying for?

 

 

I've heard the same tale about a Liverpool boat too.

 

Richard

 

I heard about it happening on a Colecraft. I guess the same thing can happen on any boat (with an integral tank) that isn't properly maintained.

Edited September 17, 2009 by blackrose

[paulcatchpole]

Mitch + Soma were doing this, from this old thread:

 

http://www.canalworld.net/forums/index.php?showtopic=3917

 

PC

[Nickhlx]

I used to sell RO systems for installation in houses.

 

10 years ago or more they used to be around £400 but nowadays around £100 is nearer the mark.. See the ads in Screwfix ...

 

For those who don't know, an RO system basically contains a coarse filter to take out physical matter down to about 5 microns, then maybe goes on through a fine filter passing around 1 micron or smaller, then through the RO membrane which passes water molecules and not a lot else - blood cells, bacteria and viruses are all too big to get through ( ! ).

 

It then goes into a storage tank ( all under pressure ). This is a normal tank which contains a sterile rubber bladder around which is air pressure at approx 8 psi. From this the water flows though a final activated carbon filter to remove any thing else and any odours and on to the tap...

 

Pros and cons...

 

You need a steady flow of raw water under approx 50 psi to be applied to the system at a rate of "a trickle" and the pure water will be produced at a rate of approx a drip a second or about 10 - 15 litres a day ( temperature dependant). This is usually achieved with a Shurflo booster pump which takes low pressure water, has a small pressurised container to store a small quantity ( about a litre) at the required 50 psi or so and applies it to the system. so it will use electricity - not a great deal though.

 

For Canal water I would suggest an extra, large, initial coarse filter at the front ( say 5 micron), with a re-useable cartridge, as this will trap much of the physical stuff and need cleaning at approx monthly intervals, depending on usage. The RO membrane should last about 4 years, and other filters about 1 year. Cost to run is minimal - say £20-30 per year.

 

The product water is stunning - Its actually visibly different to even tap water. Tea does not have scum / skin on it, vegetables taste much more of what they should taste of, you won't use / need to use so much coffee, or tea in the pot, and the Scotch tastes so much better. The kettle has not furred up since new, some 5 years ago... Additionally, we use the water for the iron ( not on the boat !!) and topping up batteries ( fellas !!) - when you come to change filters, it will completely change your view on even tap water - the amount of muck trapped from "clean" tap water is shocking, although will probably do no harm - I wouldn't hesitate to trust and drink the product water using canal water as the source.. and as a bonus you will know that there are very low concentrations of anything in it - just clean water. Nitrates are about the only chemical it doesn't reduce by approx 99% , only about 50% , and people in the farming regions of Anglia, where run-off into the rivers etc cause the nitrate concentrations in tap water to be high, have special Nitrate filters added to their systems -supplied FOC by Anglian water.

 

We have had one at home for approx 12 years and will definitely have one in our next house... Volume occupied by the system is approx a cube 15" x 18" x 18" tall and would easily go in a cupboard under one half of the sink, so may be a struggle for some - you could mount the Shurflo pump at one end of the boat ( away from sleeping area) and the storage tank remotely from the under-sink area, and just have the filters under the sink.

 

For weekend use, we just have a 5 or 10 litre clean water tank on the side of the sink for drinks / cooking, but if I were a CCer / liveaboards I would probably fit one, partly for peace of mind and partly because I much prefer it...

 

Nick

[NBMike]

Hmm. Very interesting Nick. I may look into it further.

Mike

[Nickhlx]

If you're putting it in your batteries or aquarium, then the water quality is as good as distilled.

 

If you're intending to drink it, then the quality is as bad as distilled. It's generally held that if you're going to drink RO water, you should be taking a mineral supplement.

 

 

You get miniscule quantities of minerals from water and potentially much more risk of picking up nasties. Some people don't drink much / any water ! A balanced diet will give you far more minerals than you need....

 

Nick

[DHutch]

Sounds plausible, certainly for a sailing boat.

 

But 10-15 litres a day isnt going to cater for most peoples total usage, to drink yes, but not for washing and showers. Our 80gal (350litre) tank lasts about two days with heavy usage. So you still have to stop at a tap.

 

 

Daniel

[Nickhlx]

Sounds plausible, certainly for a sailing boat.

 

But 10-15 litres a day isnt going to cater for most peoples total usage, to drink yes, but not for washing and showers. Our 80gal (350litre) tank lasts about two days with heavy usage. So you still have to stop at a tap.

 

 

Daniel

 

 

Agree - Domestic RO system output is only intended for drinking and cooking - for washing and showering etc, domestic tap water is fine. For on-boat washing and showering, there is a range of "whole house" filters that would provide adequately clean filtered and sanitised water in volumes for showering and washing. I think the main water tank could be used for storing this "cleaned" water, from a system like Mitches, with possibly chlorine tablets dropped in as a final security measure...

 

But have you the need ? it will take up space and funds and whilst the hose may take a while to top up with, it will suit most...

 

Nick

Edited September 17, 2009 by Nickhlx

[DHutch]

Repeat thread requiring merger, methinks.

Done

[Phil Ambrose]

Apparently you can buy a 100gallon per day unit for less than £100 - which doesn't sound too eye watering. No idea about running costs though - but is it not just a pump?

 

I think you will find price is around £1600-00 for this sort of unit, they have them for sale at Marine Mart.