Your thoughts and experiences with various types of water purification

[art_arkin]

Despite the use of a 5 micron filter I still seem to get drying

marks on film, particularly 35mm. Water here in London is quite hard

so I?m beginning to consider going down the water purification

route. There appears to be no shortage of very affordable water

distillation units on the market but my concern is their running

cost. It seems the lower end models take a good 3.5 - 5 hours to

produce a gallon of distilled water. Does this mean the machine is

boiling water all the time? At this kind of rate my electricity bill

would soar through the roof and it would probably be cheaper to buy

pre packaged water at the supermarket.

 

Does anyone know a cheap source of distilled water in the UK? 1

litre costs about 70 pence ( US$ 1.3 odd ) at the super market so

this is hardly a viable route for photographic use but if one could

buy from an industrial supplier delivering 15+ ltr containers for a

reasonable sum it would be of interest.

 

Alternatively you can apparently collect the water from a

dehumidifier though I imagine this would need further filtration to

remove dust and airborne particles picked up in the process not to

mention being much slower.

 

Finally has anyone used 'Brita' type carbon cartridge filters for

preparing final rinse water? These could be a solution of sorts and

very economical.

 

Any thoughts or experiences, much appreciated.

[bj_bignell]

Arthur,<br><br>

I would try using a Brita jug, or a faucet-mount filter, before starting to buy water. They can be had for relatively low prices, although the UK Brita site doesn't list the faucet-mount systems. Something like <a target=_blank href=http://www.brita.com/products/faucets.shtml>this device</a> or <a target=_blank href=http://www.brita.co.uk/action/products/jugs/product?which=Optimax>this jug</a>.

Also, have you tried using Kodak Photo-Flo? It's very economical (I'm using it at about 1:600), and it was the end of drying marks for me.<br><br>BJ

[silent1]

For about a year, I developed my film with purified water sold from dispensers at supermarkets (to refill jugs I supplied); that water was treated by reverse osmosis, carbon, micron filtration, and ozonation, and this worked very well. Since moving to North Carolina, I've been unable to locate a source of this very inexpensive purified water (it was 35 cents a gallon), so I've been using purified drinking water (purified by distillation and ozonation) sold by the gallon, recently increased to 99 cents a gallon. This also works well, but I'd love to cut this price by half or more, especially because my water consumption will rise preciptately soon, when I finish setting up to print; I'm thinking it may be time to find or build a still to purify my own water.

[j_robinson2]

In the western USA we have WalMart that sells distilled water for 58 cents a gallon. The last two rinse baths & the photo flo in this stuff help keep the film drying prisine.

[michael erlich]

You need not use distilled water for the entire wash, just the final rinse in wetting agent. If your water is very hard (high concentration of dissolved minerals) a dip in plain distilled water followed by a dip in distilled water with wetting agent will eliminate drying marks.

 

Carbon or particulate filters will not remove dissolved minerals.

[john_cook1]

I have experienced London water whilst on holiday from the States. So I understand your problem. Almost as bad as Los Angeles.

 

There are two general requirements for darkroom water. The developer water must have a stable, constant ph from month to month. And the rinse water used for the sequestering agent (such as Kodak's Photo-flo) must be free of particulates and dissolved minerals.

 

Both of these requirements can be met with water filtered by reverse osmosis marketed for chemical and medical lab use. And of course distilled water.

 

My suggestion is to avoid your own purification equipment and to not shop for water at a store. Both rather pricey.

 

I have found listings in the yellow section of the telephone book under "water, distilled" and under "chemicals" for this type of water. These vendors supply local hospitals, etc., with pure water at a much better price.

 

Locally (New England) the going price is well under $1.00 per gallon. Supplied in 5-gallon cardboard cubitainers. 5 cubitainers or 25 gallons minimum to qualify for free delivery to my door.

 

In your case, an inline filter would be generally helpful, but not sufficient for the final sequestering rinse.

 

I have used a Brita filter, but had lots of carbon filter material leak into the bottom (clean) water. They require very careful handling. Okay for developer, but again probably not sufficient to make your photo-flo safe from all minerals.

 

I have seen water softeners in action in Ontario, Canada. The unit put some sort of salt solution into the tap water, making it feel almost greasy to the touch. Soap then made lots of suds, but I couldn't seem to rinse clean in the shower. That set-up can't possibly be good for film development.

[ronald_moravec1]

Yes, no to the Brita. Ok for drinking though.

 

5 micron cleaned up all my problems except that what was airborn. I would start again with new solutions in new or WELL washed bottles. It took a while for me to clean up my act until the storage bottles got cleaned out. I didn`t realize there were contaninents lerking there.

 

Do not reuse solutions. Silver seems to precipate from fixer as it sits and it transfers to the next film and does not wash off. Use the used film fix for the first of a two bath for paper.

 

Do all this before you go to a distilation unit. I`m willing to bet you will not have to get one.

 

Another hidden spot is the piping between the faucet and the filter. It`s filthy in there. Flush well and store water in clean jugs for future use. I do about 20 gallons at a time.

 

Between all of the above and an air filter, my spotting has gone to zero.

 

I tried purchased distilled water, but it didn`t work. All the other steps I named above were necessary.

[chris_waller]

Arthur,

 

I live in Bristol and our water is hard, having drained through the limestone of the Mendip Hills. I use a 10 micron filter made by Ametek of the US but available in the UK through Fileder Filter Systems of Maidstone in Kent - 01622-691886 or email 'office@fileder.co.uk.

 

I have discovered that the way to avoid drying marks is careful use of wetting agent (I prefer Paterson's or failing that Tetanal Mirasol).

 

I also collect the water when I defrost the fridge and use that instead of distilled water. And, yes, you can use the wate from a dehumidifier. But if you want a still, try Just Magnotherapy (www.waterdistiller.couk.com). They do a low-wattage still. Other than that try a gallon of battery top-up water from such as Halfords, the car-spares people.

 

Like you, I have found that drying marks occur more on 35mm film but I never get a problem with 120. The other day I processed a roll of 35mm and left it to dry naturally (i.e. I didn't switch on the film dryer) and I got a roll of perfectly clean negs. Subsequent to that I have tried allowing the fil to dry naturally for an hour or two before turning on the dryer and that seems so far to cure the problem of water marks on 35mm film.

[chris_waller]

Arthur,

 

Just Magnotherapy (of Nottingham) sell a still which is barely 600 W and produces about 1 litre per hour so that's about 5 pence per litre (plus the cost of the still amortised over the number of litres it produces in its lifetime).

 

And carbon filter cartridges are available for the Ametek filters.

[test11664875106]

Arthur, it's very unlikely that you have to resort on distilled water - I'd been developing films in water of different pH (soft in Paris, extremely hard in Copenhagen, something in between in my hometown in Russia), regardless of quality of tap water I still had to use wetting agent after final rinse. Otherwise spots will show up.

 

Distilled water of course shouldn't produce any spots, but...it's much cheaper to use wetting agent, while you can't tell difference in the results.

 

P.S.: The water in Copenhagen is _really_ hard - calcium builds up in a kettler within a week or two, so I can't imagine London's water is _much_ harder from practical point.

[big toys are better]

Since distilled water is so expensive, try deionized water (or good spring water or well filtered tap water) for non-developer steps and reuse the distilled water for a final rinse with just a touch of wetting agent-- far less than Kodak suggests if using Photoflow. That should minimize spotting and streaks.

[jason_stilz]

I actually bought a reverse osmosis unit. It was very cheap and works great. I get no drying marks at all. These guys were very helpful and cheap, they are scientist not sales people with no information. http://www.aspwater.com/shopaff.asp?affid=15