# Best way to purify water?



## Gadge (Apr 18, 2008)

Looking through, its either RO or DI water. Whats best or cheapest?


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## Neil_S (Oct 26, 2005)

RO with a DI step.

I have a 4 stage RO filter with the final stage being a DI filter.

If you were to try and filter from tap source, just using a DI filter, the crystals would quickly become spent, hence why it doesn't generally take long to get water spotting back with an Aquagleam filter for instance.

In my RO setup, source water is 270 parts per million, it is 5 parts per million by the time it gets to the DI stage which polishes the water to get 0 parts per million and perfect water.

The RO membrane (the third step) does the main part of the job, removing about 240 parts from the water, it carries away these excess parts through waste water, 3 litres per 1 litre pure in my filter.

If your on a water meter it may sound bad, but I am and it hasn't led to extreme bills, a bit more maybe, the waste water is still safe, just has a higher parts per million measurement than source as it is carrying away those extra parts.

For RO filters I can recommend, RO-man.com


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## Gadge (Apr 18, 2008)

Thanks, im in the NW so not too shure how far to filter the water. Also i'll wash the car once every two weeks say. So is the RO still the best option?


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## Neil_S (Oct 26, 2005)

What do you want to use the water for?

I've been working in Cheshire for a fair bit of this year and that water seems reasonably soft compared to where I live in the south.

I would say you are best advised to use the water for a final rinse so you can let it air dry without water spots.

Use tap water for washing


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## Gadge (Apr 18, 2008)

well i just ordered this:
http://www.ro-man.com/shop/product_info.php/cPath/22_90/products_id/258

yes its for final stage rinse, plus i suppose it has lots of other uses! i have a big pond so i can use it for that too.


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## craigmk6 (Oct 19, 2007)

my mate has a few of what he called ro-40 and he wants £160 for them i think. 

is that good? (if you know what one he is on about)


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## Gadge (Apr 18, 2008)

You mean a RO setup that does 40 gallon a day for £160? If so that isnt good, as i paid 70 odd quid for 75 gallon one.


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## craigmk6 (Oct 19, 2007)

robbin ****! lol i will give him a telling tomorrow.


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## pvr (Oct 1, 2006)

Is there a novice guide to this? Just read through that link and I have no idea what it means ...

I want to install something that will purify the water for the final rinse, and have all the space in the world to put units near the tap etc. but don't know where to start. Help appreciated ...


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## Gadge (Apr 18, 2008)

pvr said:


> Is there a novice guide to this? Just read through that link and I have no idea what it means ...
> 
> I want to install something that will purify the water for the final rinse, and have all the space in the world to put units near the tap etc. but don't know where to start. Help appreciated ...


the one i ordered does the job great! Takes about a square foot of wall space up and it very easy to install. You just need to be near a main supply and be able to drain the water somewhere near.


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## pvr (Oct 1, 2006)

So would it be best to get some plumbing done in the garage? There is an outside tap at the outside of the garage.

When you say drain the water - is that waste water?


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## Gadge (Apr 18, 2008)

if your keen on getting one, best to get it and way up your installation options. 

Yes, its the waste water.


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## monzablue16v (Jan 24, 2008)

Or waste water to a Water Butt water for watering the garden during the drought.


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## Neil_S (Oct 26, 2005)

monzablue16v said:


> Or waste water to a Water Butt water for watering the garden during the drought.


Absolutely.

I used to store the waste water in drums, but no longer could be bothered storing so much water. In summer I do water the flowers with it though.

It is perfectly fine for washing the car with and I used to use it through the pressure washer and it was fine.

It has slightly more parts in the water, but is completely fine.

My ideal setup would be 1 tank for waste, 1 tank for filtered. I would intend to hookup the pressure washer to the waste tank and therefore have an RO solution with no waste.

I've hooked my RO filter with hozelock adapters. Can explain how, if it would benefit anybody.


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## TOGWT (Oct 26, 2005)

pvr said:


> Is there a novice guide to this? Just read through that link and I have no idea what it means ...
> 
> I want to install something that will purify the water for the final rinse, and have all the space in the world to put units near the tap etc. but don't know where to start. Help appreciated ...


*Water softener:*
Salt does not directly soften water; salt is only used to regenerate water softeners. The salt creates brine, which flushes the resin bed in the water softener to restore the univalent sodium ions. The sodium does an ion exchange with the hardness metals (calcium, magnesium, etc), so basically the hardness metals are replaced with sodium.

The water to be treated passes through a bed of the resin; negatively-charged resins absorb and bind metal ions, which are positively charged. The resins initially contain a divalent (single) hydrogen, sodium or potassium ions, which exchange with divalent calcium and magnesium ions in the water. This exchange eliminates precipitation and soap scum formation. As the water passes through both kinds of resin, the hardness ions replace the hydrogen, sodium or potassium ions which are released into the water. The "harder" the water, the more hydrogen, sodium or potassium ions are released from the resin and into the water

*Water Filtration:*
*a) Deionised *(DI) water - is water that lacks common Cat ions (Ones with positive charges, 
i.e. Na+, Ca+, CU++, Fe++ ) and Anions (ones with negative charges i.e. Cl-, Br-), so you are left with OH- and H30+ (effectively H20 and H+) this is achieved by passing the water through an Ion exchange resin. This is usually an organic polymer with a surface that simultaneously traps one type of ion, while releasing another, hence the name ion exchange; de-ionized water can still contain bacteria, end toxins and organic compounds.

To provide spot-free vehicle washing and to remove hard water minerals, raw water is passed through a pre-cleaner and then through a cartridge that contains mixed bed resins, a Cat ion (sacrificial anode) and anion resins, the process is that through an exchange of mineral ions for sodium ions, mineral ions are attached to the resins. Once the resins are depleted, which can be checked with a total dissolved solids (TDS) meter, periodically they require replacing. One of the advantages of DI water system is mineral free water and little to no wasted water. _This is a popular unit used by detailers in the US_ -CR Spotless - http://crspotless.com

*b) Reverse Osmosis *(RO) -is produced by forcing the solvent (water) through an ultra fine membrane (filter) under pressure (leaving the ion in the water behind) the water system inlet takes water to a pre-cleaner sediment filter, then it is passed through a membrane, which captures the minerals and has to be flushed constantly to wash the minerals from the membrane, and then on to the water outlet to drain. Chlorine will damage the membranes over time, and will eventually "by-pass" the membrane, producing a mildly acidic solution. It requires up to 10-15 gallons producing 1-gallon of pure water. The RO system is slow and not very energy efficient due to its water requirements as opposed to its output of pure water (i.e. 1500 raw water to produce 100 gallons RO water)


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## pvr (Oct 1, 2006)

THanks for that! Very helpful in understanding the workings.


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## ianFRST (Sep 19, 2006)

get the merlin system, purify as you go, with no waste


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## Neil_S (Oct 26, 2005)

The reason you have waste water is to preserve the RO Membrane.

The Membrane is very fine and as the water is forced through the parts in the water are removed, the Membrane is then continually flushed with water so the parts don't block it completely.

This waste water contains those excess parts and is flushed away.


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## Neil_S (Oct 26, 2005)

ianFRST said:


> get the merlin system, purify as you go, with no waste


Whats the Merlin system?

The problem with these so called purify as you go systems is that they either do not work as well as RO, or they require, refilling or filters replacing regularly, which is far more than the cost of water.

I pay about £3 for 1000 litres of water, so that is enough to rinse my car about 10 plus times.


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## ianFRST (Sep 19, 2006)

http://www.ro-man.com/shop/product_info.php/cPath/22_94/products_id/130

ive seen ALOT of window cleaners have this in their vans..... but when ever ive asked them, they have no idea what it does, they just buy it :lol:


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## Neil_S (Oct 26, 2005)

Quite alot of money that though, I think I'll stick with my £80 50 gallon a day job!


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## Az234 (May 3, 2007)

I keep marine fish and I found the best RO units for the price are from osmotics http://www.osmotics.co.uk/4-stage-75-gallon-per-day-reverse-osmosis-system-p-102.html

for £65 it is not bad but I would recommend getting one of these it makes it run a lot quicker and less waste is produced.http://www.osmotics.co.uk/adjustable-selfregulating-booster-pump-p-185.html?cPath=29 but now it is getting expensive.........


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## Bennai (Jul 10, 2007)

Az do you post on any of the marine forums??

i was going to suggest that a few guys from here have a look on the aquatics forums for people selling second hand RO units, there are deals to be had there.


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## Gadge (Apr 18, 2008)

Well i've been using my setup for over a week now and its great, takes a while to make the water (2hrs for 18.5ltrs) but i dont mind. Its great to drink, superb for rinsing the car, and its doing my pond wonders with getting rid of the algea!

I bought an inline IN and OUT meter for it and i get 100ppm going in, which is pretty good for RAW water and on the OUT i get 1ppm just on the RO, and get 0ppm after the DI filter (only use the DI filter for car rinsing).


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## Az234 (May 3, 2007)

Yeah Marine fish uk

TDS meters are brilliant as it lets you know when the unit is not working propperly


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## yin (Dec 29, 2005)

Neil_S said:


> RO with a DI step.
> 
> I have a 4 stage RO filter with the final stage being a DI filter.
> 
> ...


Thanks for the info but how much waste water do you get?

just re read and found it thanks


Neil_S said:


> The RO membrane (the third step) does the main part of the job, removing about 240 parts from the water, it carries away these excess parts through waste water, 3 litres per 1 litre pure in my filter.


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