Using distilled water in mixing chemistry

[unixrevolution]

It's been a few years since I have developed black and white film at home. In this case it'll be HP5 at 250 ASA, Ilford film developer and Ilford fixer.

It seems worth it to use distilled water to mix up the developer and the fixer concentrate to ostensibly help prevent dust/particulants settling on the negs. Is it worth it? Is this overkill, or should I just use regular tap water? Naturally I'll be using tap water to wash the film after fixing it, and then using distilled water with Photo-Flo before hanging the film to dry.

So what do you folks do? And what is this Ilford washing regimen that I've run across on RF Forum?

Thanks for your response!

Distilled water is so absurdly cheap compared to the cost of other chemicals, the cost of film, and the opportunity cost of going to take the photos, that I can't see cheaping out on this step if you're really worried. I would use it, at the VERY least, to mix up the developer. I would also say it should be the final rinse at the end, but I am terrible at practicing what I preach in this regard.

 

[Calzone]

Cal, your tap water measures acid even after the chlorine has dissipated?
New York City water pH is usually claimed to be neutral to slightly alkaline.

Chris

Chris,

I can believe that NYC tap water is slightly alkaline. I run a humidifier in my apartment for my skin, for my musical instruments (guitars), and for my printers (to prevent my print heads from drying out that will lead to clogs). The granite counter tops gets coated with what seems like a calcium deposit.

For mixing chemicals I use HPLC grade water that is first distilled and then scrubbed by reverse osmosis. In my lab I have this system, so why not exploit it.

From P's post I suspect that this 18 mega ohm water is acidic and because of this it works very well as a stop bath since developers are alkaline.

Not sure how the acidity of this water effects my mixing of developers, except it might reduce its strength, but the solids dissolve and mix rather rapidly. I know I have a very-very low amount of impuritiess being introduced when I mix my chemicals, and that is why I use it.

Working in a research lab has its benefits.

Cal