I had some leftover developer and blix mixed up back on 28 Nov 09, there was only about 200ml of each left in a couple of squeezed out 500ml pete plastic water bottles. After doing some printing last night, I made a test print using the old chemistry. The drum smelled a little different when I opened it than it did when using the fresh mixed chemistry, but the interesting thing is I can't spot any difference in the prints. The subject was a flower, and the shades of pink, white, yellow and darkish greens match perfectly. Processing was done at 20-21C for 2 minutes. I do mix the chems with distilled water and store in free reused PETE 2 litre soft drink and 500ml water bottles. Now does anyone know a simple test to determine if blix is still good?