dev time for re-use developer

Thanks very much Tim, such a detail explaination of concept and consideration.

Thats exactly what i observe so far, see stain at 3rd print.

I was using pinsta small bottle, extract first 20 mil to syringe. After an hour, what remain in bottle turn yellow.

I recently found some 30ml bottle from aromatherapy shop. I think i carry few more and stick with 2 print per syringe