How much stock solution do you mix?

[John Kasaian]

I've been mixing gallon jugs of the stuff, but during the past year I've had too many experiences with stock solutions going bad, so I'm thinking of switching to 2 liter jugs instead.
How much stock solution do you mix at a time?

[Michael Clark]

I mix the gallon packets of paper and film developer chemistry, and buy the liquid F-5 fixer concentrate in one gallon jug. During the summer is when I start to worry about having to much mixed up and going bad, not so much during the winter. The concentrate fixer seams to hold up fine and its kept in the garage during summer. I think half gallon bottles would be better, it takes me about a month to go through a gallon of stock solution developer, but some times more.

[stawastawa]

I store stock solutions in small containers, so less likely to get disturbed and oxygenated and go bad. I have moved away from storing chemicals in less than 1/2 gal containers unless I know I am printing large often.

[Doremus Scudder]

Almost all my chemicals for film developing and printing get mixed "one-session" or for two consecutive sessions, then get tossed.

For film developing, my developers of choice are all in concentrated, long-shelf-life stock solutions: PMK, Pyrocat, HC-110, etc. I use theses one-shot. Occasionally I have a small amount of PMK go bad on me before I can finish an entire bottle of concentrate, but the loss is small.

Print developers seem to last fairly well in stock solutions. Bromophen and Zone VI (and even Dektol) developer last six months to a year in stock solution if stored carefully (I do use gallon jugs). Liquidol and Ansco 130 are really long-lived. These, of course, get mixed down into working solutions that I use for one day or a bit longer, depending on the individual developer and my throughput. I more and more tend to mix basic developers from scratch just before use (D-72, Selectol Soft, etc.). These, again last for a session or a bit more.

Fixer is from liquid concentrate, either Ilford Rapid Fixer or Hypam or TF-5. I only mix what I need for the session and keep track of capacity. Only rarely have I had to discard fixer concentrate due to sulfurization because of age.

If you use acetic-acid stop, you can mix it and use it till it is exhausted without worry. I mix citric-acid stops for one-two sessions since they store poorly.

My selenium toner gets filtered and replenished, as I have described here often. I mix wash-aid from scratch one-session.

Best,

Doremus

[Pete Oakley]

I use the Patterson Orbital system so I only need 300ml of liquid in the tray for 4 4x5, 2 5x7 or 1 8x10. I only mix 1 or 2 litres of D-76H as I use this 1-1 and 1 or 2 litres of TF2 fixer depending if I have roll film to process as well. I always leave the developer overnight before I use it but I can't remember why, if I ever knew.

[esearing]

I am an infrequent practitioner so I seek longevity of stock and/or working solutions. Trying to remedy that by doing a little every month. I also only shoot a few 4x5 sheets a month and print mostly 8x10 so do not need large volumes.

Film developer I use one shot and buy in 1 liter size HC-110, Pyrocat HD in Glycol.
Fixer a gallon of TF4 or Ilford rapid fix seems the most economical for my needs. working strength I make a Liter at a time and sometimes replenish if working frequently.
Print developer mix a gallon stock and dilute from there. Ethol LPD seems to hold up even diluted to working strength for a few months.

[chassis]

I am migrating to 0.5 liter bottles after 35 years of using gallon jugs. This is after starting C-41 processing myself, and mixing several gallons of each chemical, storing in 1 liter and 0.5 liter bottles.

I bought bottles at K-Mart. Sweetened drink (vitamin water, for example) bottles are made with PET (good, meaning low, oxygen permeability) and reasonably good closures (screw caps). 1 liter bottles are available for US $0.69 each. About the same, or less, than can be found on line, after shipping cost is included.

I use D-76 one shot, diluted 1+2 from stock solution. 1 piece of 4x5 film uses 3 ounces of stock solution in a BTZS tube, using my stand development method. This means I can get almost 50 sheets of 4x5 film processed with 1 gallon of stock developer solution. So in the ball park of US $0.02 developer cost per sheet of B&W film.

Using four 0.5 liter bottles is a good way for me to preserve developer freshness with the monthly volume of film I process.

p.s. For C-41 processing I use mainly 1 liter bottles, because of my development method. I use a Paterson tank for one sheet of film, and this requires about 750 ml of fluid, per each chemical. So I decant 750 ml into the tank, follow the process, then pour the solution back into the 1 liter PET bottle. My C-41 process is not one-shot. This may change as I improve my workflow.

[Gary Samson]

I use 1.5 liter glass wine bottles with stoppers that allow you to create a vacuum after use. This has been a very successful way for me to keep Pyrocat M for months after mixing. I have never had developer failure using this method.

[Luis-F-S]

The least quantity possible. Still I end up throwing a lot of it away. L

[Jim Noel]

I mix no stock solutions. I mix appropriate quantities at proper dilution as I prepare to use it. This is true of both liquid concentrates and powders such as Dektol. Those which I mix from basic chemicals are mixed in one shot usable quantities.