How long should this developer last

Once mixed and placed in a floating lid, covered container, How long should I reasonably expect my Ilfotec DD-X to remain good? If unmixed in an opened, but tightly sealed bottle kept in a cool dark place (my darkroom) should I be able to expect it to last longer than the three months stated by Ilford? Thanks in advance.

There are too many variables to give a definitieve answer. How warm is your site, are there temperature variations, how old was the stock, did you use it forst or keep it unused, etc.

A film leader test can help here. Load your film and use the leader you clip off with 35mm, or keep a roll of 35mm film around to check with. Flash 3" of film in the case of a test film.

Drop it in a clear beaker with the white lights on. See how long it takes to go black when new.

If you have not used the dev for a while, see if the leader still deveops to balck in the same relative time frame. It is a loosy-goosey way to see if your developer is going off.

Mike, thank you. The developer has not been mixed, as I was only considering doing it for use over a couple of week period of time. The bottle of developer I have is half full, has always been in a dark cool place (74 degrees or so) and was opened about six months ago. The round trip to get more is about 2 to 2 1/2 hours and about 125 miles total in a car which gets 17 MPG. That equals an expensive bottle of developer. I will, as always, have a list of activies as I drive from the sticks to the city. Bill Barber

I have no idea how long it will stay viable. If you want longevity, you should invest in dispenser boxes with bladders. You van pull all the air from these and the chems will last a very long time.

My experience with DDX suggests YES but it was at a slightly cooler temp range of mid 60s. However I'd be inclined to cover it with an inert gas such as you get with Protectan to prevent air getting at it any further or decant into smaller bottles which can be filled unless you can use it in a matter of a few weeks from now. Ilford have always got to be conservative when giving storage times.

With Protectan I got about a year out of my DDX.

pentaxuser