water filters

[Mark Kononczuk]

Hi,
I've noticed in photos of darkroom setups that people often have 2 water filters. What are they for? I installed one for particle matter but it is not enough. Everything is fine until it comes to the rinse. i use distilled water for everything except rinsing. I filter the developer and fixer, but when it comes to rinsing, i get these little white specks clinging hard to the film. i remove them manually with my fingers but I think this might scratch the emulsion, I'd rather remove these specks with a filter beforehand, but what could they be? what 2nd filter should I install?
thanks

[Drew Wiley]

You need different ones for hot versus cold lines. If you have an automatic tempering valve for working temperature, it probably needs protection from particulates prior to water reaching it. Otherwise, you'd just have to be certain a single filter didn't have to withstand excessive hot water. Since I use fully hot water right out of the line for sake of dissolving sodium sulfite, for example, I can't diminish the line temperature of that particular line. Conventional hot water heaters are infamous for building up calcium deposits, and then shedding bits of that into the line, like what you're probably seeing on your film. Cold water lines sometimes bring in rusty or organic contaminants. Our water here is very high quality, so I freely use it for nearly everything except final film rinse or highly technical applications. In fact, my own filter is disconnected; but I might re-attach it my next maintenance session for sake of my print washer. One of my darkroom faucets is having valve issues.

Another potential culprit is water mold (Saprolegnia). You need a pretty fine filter for that. But simply mixing fresh dev and fixer as needed, rather than re-using it, is a better anwer. Also beware of buildup of deposits on you measuring graduates or developing tanks too.

[Renato Tonelli]

I use two filters, one for hot and one for cold water, as suggested by Drew. Long ago, I was getting stains (rust?) on my negatives and the use of the filters solved the problem.

I have been using these:

https://deltaphotosupplies.com/darkroom---water-filters.html

[Drew Wiley]

One thing I forgot to comment on is that the very most important time for using distilled water is during the final rinse, following the wash step.

[LabRat]

Dual filters means there is one filter after another... The first filters out most of the particulates, and the second catches what might get past the first filter... Some locales might not need the second filter, but some do (and depending on what's flowing through the system at the time)... A non-scientific test is to open a filter every few weeks and see what has collected on it, what color the filter is then, and look into the bottom of the filter housing to see if anything has collected there...

The GE filters at the home store cost about $20 and work well, but note that using the finest filter cartridges (in some systems) seem to cause a disturbance in the water causing milkiness, tiny bubbling, and seems to start "knocking" the chlorine gas out of the solution (in highly chlorinated water systems)... And don't forget to change filter cartridges on a regular basis...

Leaving film soaking in distilled or deionized bath for 10 or 15 minutes after wash soaks wash water (+ minerals) out of deep emulsion before photo-flo bath and can reduce subtle haze that can dry on film...

And flush out darkroom water lines before processing to flush out what can collect while you were gone...

Hot water lines should be filtered too, but look for the temperature rating on the filter before installing... I had to install a new heater heater for the lab, so I installed a filter on the cold water feed to keep heater cleaner...

LA here has slightly harder water + significant amounts of algae/particulates + lots of old plumbing/mains, but other systems have their own local variations, so be on guard...

Steve K

[Bill Burk]

One thing I forgot to comment on is that the very most important time for using distilled water is during the final rinse, following the wash step.

Haa exactly! Used to have a reverse osmosis filter and this served well for the final rinse. But after a couple leaks I decided I didn't want to take any more swim tests and I shut the thing off and sealed up its pipe. Since then I switched to bottled distilled water.

[Tin Can]

Temp is also critical

I use HASS filters with tight temp control and tempering tanks for Gas Burst

and mix all chems with distilled

http://www.hassmfg.com/photog.pl/1213638750-2927

[Willie]

One thing that can help, even with inline filters is one at the tap where the water comes out. Put itscrew it on for final filtering and take it off when using the water for other things. Just one last step in filtration.

[peter brooks]

(An answer not really addressing your original question, but...)

For what it's worth I don't use filters, I use water from the tap (heated, of course) for all processing but always use distilled water for the final film rinse (with Photo-Flo) in a tray, and often for the penultimate rinse also (in the drum or tank).

I used to get a lot of rubbish on the neg (apart from just the content that is), and I got that advice from an old hand at a photography club. Made a world of difference.

*** Caveat: I have had distilled water (just once) go cloudy and have bits floating in it, don't know if this was just a bad batch, too old, not sealed properly etc. but check it before use if you buy the auto type in plastic containers.

[Mark Kononczuk]

I can control every step by using distilled water and by filtering. Everything that is, except the rinsing inbetween the fix and the photoflo. Does anyone actually use distilled water for this rinse? You would need gallons of distilled water, surely?

[peter brooks]

I can control every step by using distilled water and by filtering. Everything that is, except the rinsing inbetween the fix and the photoflo. Does anyone actually use distilled water for this rinse? You would need gallons of distilled water, surely?

Again possibly veering a bit off-topic but I work in a school and our science department constantly make their own distilled water - automatically, in a thing that looks a bit like one of those old hot water cylinders.

There will be plenty of scientific folk on this forum who will know how this is done and what is required. The cost to purchase and run such a thing may be prohibitive, I have no idea.

As I mentioned above I sometimes use distilled water for the penultimate rinse as well (the one before the Photo-Flo, which I see as a kind of 'bonus' last rinse, although it is more of a dunk!)

[Drew Wiley]

Your own distiller might prove energy intensive and costly; plus you have to clean them out a lot as calcium scum builds up. Best to use it for making moonshine instead, which at least one can sell, probably better than photographs! I'm in a quandary over that very question right now. If I ever have enough block of time to get past the kindergarten level of dye transfer printing, I'll need a very large quantity of distilled water on hand, because the whole printing workflow is extremely pH sensitive. But for ordinary photographic printing, just going to the supermarket and picking up a few gallon jugs at a time for 75 cents apiece does the trick.

[Ron McElroy]

Again possibly veering a bit off-topic but I work in a school and our science department constantly make their own distilled water - automatically, in a thing that looks a bit like one of those old hot water cylinders.

There will be plenty of scientific folk on this forum who will know how this is done and what is required. The cost to purchase and run such a thing may be prohibitive, I have no idea.

As I mentioned above I sometimes use distilled water for the penultimate rinse as well (the one before the Photo-Flo, which I see as a kind of 'bonus' last rinse, although it is more of a dunk!)

Where I used to work we had water distiller that looked similar to this one.

https://www.purewaterinc.com/DP850-Dental-Water-Distiller

We had a large offset printing press that needed lots of distilled water in mixing fountain solution. Since retirement I now buy distilled water at the store as I had done in the past.

[Drew Wiley]

Let's see - 9 hours at 1100 watts to produce 7 gallons maximum distilled water, whereas one can buy that amount at the store for 7 dollars or less. Which would be more economical these days? And smaller home-use 115V distillers would be even more expensive to operate. But another relevant question would be, what do you do when the store runs out?

[Mark Kononczuk]

So, if the pre-photoflo rinse has to be running water, how do you get your distilled water to be 'running' for half an hour?

[Tin Can]

I don't flow distilled, but use it at every step

I buy 4 gallons from Kroger delivered every week

I make coffee and food with it too

I can process film and food for 6 months right now

IF Kroger fails, we are all goners

I almost never use any type of Photo Flo, don't need it

4 more gallons coming today

and my local Farm Share today also delivered

[Drew Wiley]

Right around here our water is mainly Sierra snowmelt brought in by aqueduct, so is of very high quality. I only use distilled sparingly, like for final rinse with Photoflo. But it's a different story in a number of peripheral coastal and inland counties, where tap water is synonymous with barely diluted Clorox plus pesticide residue. That's on good years. This year it's more like mud combined with decaying fish guts. Drove past a reservoir yesterday where the pelicans were just sitting around the rim of rapidly of an evaporating mudhole for the easy pickings. And the endangered Coho salmon runs are really going to have a tough time surviving. Too little running water, and even if they manage to get upstream, if the water is too warm, they're unable to spawn.

[LabRat]

I can control every step by using distilled water and by filtering. Everything that is, except the rinsing inbetween the fix and the photoflo. Does anyone actually use distilled water for this rinse? You would need gallons of distilled water, surely?

There's a famous story from a photo rep about when AA invested big bucks in a water purification system for final washing of prints, but started getting staining and early decay of prints... He called the paper mfg (Ansco?) to give 'em hell about their "defective" paper product several times, and finally a rep was sent out to survey the issue...

The rep saw everything was ok, but then noticed the water purification system, and said he knew what the problem was...

The system was so efficent, that it removed all the minerals from the wash water, but those minerals were also needed to aid the washing process, but now the water was just naked and devoid of minerals, so the solution was to turn off the system and bypass it...

It worked, and the prints were washing normal again...

That rep became a legend among reps...

Steve K

[Mark Kononczuk]

Yeah, well, where do you go from there?

[Mark Kononczuk]

So you don"t need to flow the wash?

[Old_Dick]

Worth watching, open my eyes. On that page there is "Homemade print washer " which some people have a problem with.