Water Purification

ColourfulOwl

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This is my first winter of owning a sailing boat, I've decided to keep mine afloat as I want to use her as much as I can. I don't currently liveaboard but am in the process of making changes to the boat to become one.

When I went to the boat last weekend the water pump had become un-primed. After faffing about I figured out how to get the pump to prime on my boat. In the process of figuring it out, I took a look at the pre-filter (if you can call it that) for the pump. I noticed there was a small amount of sediment in the mesh and a weird film like substance (I'm guessing lime scale) sat on top of the water that was in the bottom of the filter. This has sort of flagged up to me that I need to look at sorting out a proper filtration system for my fresh water.

From a filtration perspective I have a good idea as to what I want to do. I want to go down the avenue of a full house filtration method with filters after the pump but before the split to the heads / galley.

My question is mostly around purification. What are people using to purify the water? I would rather avoid going down the avenue of chemicals, IE chlorine, and am currently looking at the idea of a UV system. Has anyone got any experience with them? Any recommendations?
 

Sea Change

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I have a standard 10" filter housing just before the galley tap, with a 5 micron carbon filter. Mostly to remove the chlorine taste- we put a tab in the tank with each fill. Seems to work and wasn't too expensive, but the housing is pretty bulky and you need enough access to change the filter. Mine went in the the under sink locker with the pots and pans, but up high so it's not really taking up usable space.
 

Yngmar

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That "filter" you have is just a strainer, whose sole purpose is to protect the pumps fragile valves from damage. If there's anything in there, you should have a look in your water tank as it probably needs cleaning.

For treating your drinking water, we went with chlorine, because you can get it anywhere and cheaply. Once a year disinfect tanks, pump, pipes, taps, showerheads with a high dose, then add a treatment dose when in use, which is usually tiny as your system is clean and you fill in only clean water. If you want, filter with a spun PP filter on your water filling hose (when you put the water in the tank). We used a fine mesh strainer here, which was sufficient, and always checked the supply water before filling.

If you want it tasting nice, add a carbon filter under the sink, making sure it's easily accessible for replacing. Do not buy boaty nonsense from the boatshow, just a regular household cartridge. Filter housings cost a bit more, but are an international standard (so can be found anywhere) and also produce less plastic waste, as you replace only the filter and not a plastic housing with it.

UV sterilization needs power, is low flow and doesn't work very well in practice, plus it does nothing to improve taste or remove particles.
 

Momac

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I avoid tank water for drinking and cooking but use use a couple of 5 litre containers which I fill from a tap .
I use 5 litre supermarket spring water bottles which I replace annually.
This method may not suit everyone.
Sounds like your pump filter had not been cleaned out for a while.
 

ColourfulOwl

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That "filter" you have is just a strainer, whose sole purpose is to protect the pumps fragile valves from damage. If there's anything in there, you should have a look in your water tank as it probably needs cleaning.

For treating your drinking water, we went with chlorine, because you can get it anywhere and cheaply. Once a year disinfect tanks, pump, pipes, taps, showerheads with a high dose, then add a treatment dose when in use, which is usually tiny as your system is clean and you fill in only clean water. If you want, filter with a spun PP filter on your water filling hose (when you put the water in the tank). We used a fine mesh strainer here, which was sufficient, and always checked the supply water before filling.

If you want it tasting nice, add a carbon filter under the sink, making sure it's easily accessible for replacing. Do not buy boaty nonsense from the boatshow, just a regular household cartridge. Filter housings cost a bit more, but are an international standard (so can be found anywhere) and also produce less plastic waste, as you replace only the filter and not a plastic housing with it.

UV sterilization needs power, is low flow and doesn't work very well in practice, plus it does nothing to improve taste or remove particles.
We dose each tank refill with Aquaclean and it tastes fine.
I have a standard 10" filter housing just before the galley tap, with a 5 micron carbon filter. Mostly to remove the chlorine taste- we put a tab in the tank with each fill. Seems to work and wasn't too expensive, but the housing is pretty bulky and you need enough access to change the filter. Mine went in the the under sink locker with the pots and pans, but up high so it's not really taking up usable space.


Have any of you spotted any negative for using the chemical tabs to purify your water? Have you tried baking with the water etc? I'm someone who would want to be able to still bake fresh bread, and I know chlorine can kill the yeast.
 

Sea Change

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Have any of you spotted any negative for using the chemical tabs to purify your water? Have you tried baking with the water etc? I'm someone who would want to be able to still bake fresh bread, and I know chlorine can kill the yeast.
We bake several times a week, never had a problem, either before or after we installed the filter.
We use chlorine tabs with every tank fill, which is generally every 3-6wks.
The strong chlorine smell only lasts for a couple of days after filling the tank, and is almost completely removed by the carbon filter at the galley tap- which is the one that we use when baking
 

Baddox

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I put a measured dose of thin, household hypochlorite bleach into the tank every refill. A carbon filter takes care of any taste issues but some chlorine still makes it through. Leaving water to stand in an open container for a while will take care of removing chlorine.

I also use the undiluted bleach splashed on a cloth to clean the marina hose end and tank filler before filling.
 

Yngmar

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Have any of you spotted any negative for using the chemical tabs to purify your water? Have you tried baking with the water etc? I'm someone who would want to be able to still bake fresh bread, and I know chlorine can kill the yeast.

No, and wife baked a lot aboard. By the way, if you like baking aboard, I strongly recommend buying a Pardini Forno Versilia (or Omnia if you like paying more for red). Very practical, saves a lot of energy and less heat in the cabin, which matters in summer.

If you have so much residual chlorine it kills your yeast, you have definitely overdosed the treatment by a lot. It takes a bit of practice to get it right. A TDS meter can help. If you also add a charcoal filter, residual chlorine will be removed anyways. We never bothered though, as with practice I mostly got the treatment dose right and we eventually fitted a watermaker, so in summer we had pristine* water.

* We found that if you never fill from a hose all summer, which always gets you some residual chlorine, you do have to add a very small treatment dose to the watermaker water tank now and then, because it's still water sitting in a tank in high temperatures.
 

trapper guy

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I avoid tank water for drinking and cooking but use use a couple of 5 litre containers which I fill from a tap .
I use 5 litre supermarket spring water bottles which I replace annually.
This method may not suit everyone.
Sounds like your pump filter had not been cleaned out for a while.
i do precisely the same, as my boat has a 50l bag type tank, and the first time i used the water in it i nearly blew chunks, was the nastiest smelliest swamp smell ever. that god it was just into the sink and not into my kettle!
anybody ever had an old cotton mop sat outside in water a little too long will know the smell i describe.
regardless of having purification tablets in it, it was rank.
i disassembled it, took it out and gave it a very thorough clean out, and even to this day i refuse to make my tea with it, preferring the 5l containers so i can SEE the water im brewing with
 

Sandy

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My question is mostly around purification. What are people using to purify the water? I would rather avoid going down the avenue of chemicals, IE chlorine, and am currently looking at the idea of a UV system. Has anyone got any experience with them? Any recommendations?
How much water are you drinking onboard without boiling? In my case it is about a few drops in my evening single malt. Water is boiled for tea/coffee. If you really have a problem with water flush the tank out several times before drinking. Bottled water is available.

I am happy to collect rain water from the sprayhood to use in cooking. Mountain burns are a source of water in remote parts of Scotland.
 
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