Hello all! The Agfa Neutol paper developers are from concetrate supposed to be diluted 1:3 once opened and stored in glass bottles as stock solution. Once I tried to not proceed the normal way, I simply opened a Neutol concentrate and used it for a couple of weeks to mix 1:11 directly from conectrate. That didn't work at all,.. after some weeks the concetrate went dark yellow/brownish and was destroyed. I hate mixing, pouring and measuring, cleaning & storing bottles... so I decided to try another approach on the same theme... using Neutol as a "mix-straight-from-concentrate" developer... This time I opened a 1.25 litre bottle of Neutol WA, poured it in a brown glass bottle (those thight-capped special seald bottles from the pharmacy) and filled the bottle up with glas-marbles to avoid air in the bottle. Evey now and the when I use 100ml of the concentrate I put in more marbles, keeping the fluid level to a maximum, avoiding practically all air inside this bottle. anyone else been down this road? The thing is that I haven't had this system going long enough to be sure if it is working, and now I am about to open a Neutol NE bottle, and maybe a Tetenal Eukobrom. Anyone?