I regularly use Rodinal 1:200 (2.5ml Rodinal / 0.5l water) for TechPan. I measure out 2.5ml of Rodinal using a medical syringe, and dump that in 1/2 litre water. Make sure the Rodinal falls straight into the water and doesn't stick to the sides of the graduate, and keep stirring.(posted 8747 days ago)