bndctcvl
Hello,
I’ve got a question.
Can you use filtered (Paterson filter) rainwater for watering?
Kind regards,
Bene
mau
Why not?
cfb_de
Hello bndctcvl,
Please choose a username 1) that’s reasonably easy to type. It would also be nice if you could include something like a real name (it doesn’t have to be your actual one) in your signature. A form of address would be nice too. Even online, the basic principles of human behaviour should be observed.
Now to your question:
I’d boil it first. Not so much because of the limescale (there’s hardly any in there), but because of other nasty dissolved substances (sulphur dioxide...) and the nasty little biological inhabitants. The Paterson filter doesn’t filter all that out. And damage to the negatives usually only becomes apparent after a few months or years.
Rainwater is generally slightly acidic. However, the pH value of rainwater is based less on dissolved ‘equilibrium carbon dioxide’ and more, in our Central European industrialised nations, on sulphur dioxide emissions, which then produce sulphurous acid in the water. Even if that only brings the pH up to 6.5–6, I wouldn’t bathe my films in it.
And I’d rather not expose the emulsion to the mould and bacteria load either. Most of the little critters would probably suffocate on the silver, but certainly not all of them. That’s another reason why I don’t want to bathe my films in untreated rainwater.
Quite apart from the fact that the water is nowhere near as clean and pure as one might think: This water usually runs off a grubby roof surface, mostly over some calcium aluminosilicates (aka ‘roof tiles’), and arrives in the barrel far from ‘soft’. One might well concede that calcium aluminate has film-preserving properties, but in a completely uncontrolled manner and at an unknown concentration, I don’t find that a good idea.
Sometimes I’m a bit baffled. I doubt anyone would give this sludge to their toddlers to drink. But bathing far more sensitive films in it (in fact, even though a person is small, they can withstand far more than a film: a person can actively detoxify themselves, a film cannot) – is that supposed to be en vogue for environmental reasons?
Oh dear. Please just take a few extra litres of water with you for film development in the caravan or dacha. Then the stability of the processes and long-term shelf life will work out fine. Rainwater would be well suited for flushing the toilet and watering the garden. I’m not keen on using it on film, just as I wouldn’t use it on small children.
Best regards,
Franz
1): I’m still using my old uni login. “cfb” stands for: Chemistry Franz Borgerding; the appended “_de” should be self-explanatory. I also sign with my real name, which makes it much easier for people replying to address me and renders the use of a pseudonym in the salutation obsolete.
dl8ram
Hello Franz,
I’ve got a question for you as an expert on water.
What do you think about using water from a tumble dryer?
Surely the levels of limescale and chemicals shouldn’t be too high?
Kind regards,
Alois
cfb_de
Hi Alois,
I know at least two people who do that. My only concern would be if they used things like fabric softener or dryer sheets.
Normally, the condensate should be almost on a par with distilled water, provided the dryer is clean.
Best regards,
Franz
dl8ram
Hi Franz,
That’s exactly what I had in mind. Since neither fabric softener nor those mysterious wipes end up in the tumble dryer, and I’m certainly not
soaking my old socks in the water, I’ll give this a go for the final washing.
I did another developer test last night and didn’t dry the frames afterwards.
Since then, I’m no longer surprised by the drying spots on my negatives :)
Best regards,
Alois
taucher
What about the fluff in the water? I always find some in mine. Do you filter it out? :)
Marion
ChristianKolinski
As we’ve just bought a new tumble dryer, I still have the instruction manual to hand.
It recommends using the condensate for irons and similar appliances – after filtering it.
So the most patient granny of them all always runs the water through a coffee filter – I couldn’t find any lint in the containers afterwards. And as she can’t iron it all as quickly as it accumulates, every now and then there’s a little canister left over for me. :)
So, in my humble opinion, there’s no reason not to use the water from the darkroom oven, er, tumble dryer.
Best regards,
Christian
SCKStef
Hello,
I’ve been using the water from the tumble dryer after running it through a carbon filter for about seven years, and at some point I started to worry about ‘residual substances’. A chemist I trust then carried out an analysis and said that although certain fragrances are present, they are in such small quantities that they have no effect. So I’m happily carrying on, and my negatives are still holding up :-)
Best regards,
Stéphane.
