Can deionised water be used instead of distilled?

[Michael Cienfuegos]

You drink TF5? Wow. Gin is as hard as I'll go.

He must be tough, have to be to survive those winters.

m

[Tin Can]

He must be tough, have to be to survive those winters.

m

I keep warm dodging hot lead...

[Jac@stafford.net]

I keep warm dodging hot lead...

Randy Moe, if you outlive me I'll kill ya!

[NedL]

It's fact. SF gets their water from the infamous Hetch Hetchy reservoir, which broke John Muir's heart, then parks it in a few big local reservoirs; but its primarily direct snowmelt. EBMUD has a similar Sierra source, with extra storage locally.....

That last part used to be true, and the water in the East Bay was fabulous. It comes from the Mokelumne. But in the 1990's there was a lot of development....and the demand exceeded what could be supplied by EBMUD. They began mixing in Delta water from the Contra Costa water district to meet demand and adding a lot of chloramine. Open a faucet in El Cerrito or Berkeley now, and the fumes are enough to make your eyes sting and it tastes awful -- at least relative to what it used to be -- still not like San Diego. That's the price everyone pays for having more people live there. I was living in El Cerrito at the time it changed and amazed that there was not more of out outcry about it.

[Fr. Mark]

We had a few weeks without much rain but last few weeks we've probably had more than CA gets all year. Twice I've had to be out driving in serious downpours. There are many good things about California from what I can tell from a few visits but water available per person is not one of the blessings there or in most of the SW. I would not mind more LF Photogs out here. Plenty of water.

[Axelwik]

There's no difference between deionized water and properly distilled water.

Deionized means it has close to zero ions other than hydrogen and oxygen (the components of water). Distillation is a process by which deionized water is made. Another process is filtering. The bottom line is that no process can result in completely deionized water. Even the water a laboratory uses to processes water samples is going to have impurities - however small. That's part of the reason analytical laboratories have a lower limit to what they can report in their results. When I analyzed water samples for heavy metals in college, the deionized water that we used to make up the dilutions was rated at 18 mega-ohms, which is certainly a lot more pure than anything you can find on the grocery shelf. Our reporting limits were just a few micrograms per liter (a few parts per billion).

What do I use in my home photo lab? Tap water. It has a specific conductance of around 250 microSiemens per centimeter with most of it calcium carbonate. I'm pretty sure that most commercially-made photo chemicals are formulated to work best with average tap water.

Unless you have unusually hard water, in my opinion you're wasting your time and money using deionized water (and probably getting worse results).

[unityofsaints]

While we're on the topic, what's the verdict on demineralised water? It's available at reasonable prices in DIY stores here.