Dear Pat,

DDX is a stable developer but you cannot tell the level of degradation by the colour of the solution, although logic suggests the darker it is would be an indicator of oxidisation.

If you are not using it all within three months, my suggestion would be to ensure no air ingress ( marbles or other ways ) store in a cool place and then test after three months with a clip test to ensure its working OK, the manufacturing of this product ensures that batch to batch variation is virtually zero so you should have no issues going forward.

Simon ILFORD Photo / HARMAN technology Limited :