Anyone having problems with Fomatol LQN paper developer?

[filip0502]

I run a student darkroom, and we have always been using Fomatol LQN for paper development.
I would mix a one-liter solution, and it would last around a month or two without any problems, but recently it started going bad much quicker.
After 2 or 3 weeks, there's stuff floating in the developer as if silver or something had separated, and it doesn't develop properly, as if it has been exhausted.
I've had this problem with the last 2 or 3 bottles, all of which have been within the expiration date.
Does anyone know of a paper developer that can be stored for longer periods as a working solution? As far as I know, all Ilford developers must be used up within 24 hours after you mix the working solution.

 

[koraks]

To be clear, you're referring to the shelf life of the mixed, working strength developer, yes? How do you store it? What kind of bottles/material, and are they full?

I can't comment on store-bought print developers; I stopped using them a long time ago. I use ID62 (or ID78) myself which I mix from raw ingredients. The working strength developer as well as the concentrates store very well in entirely full, glass bottles. 1-2 months is generally not a problem.