Sorry for my English.
I use reel agitation and it was very interesting for me what is going on inside Paterson tank. Is agitation effective or not? How bottom layers of developer mix with middle and top layers? Because main task of agitation (except stand approaches of development) is to move exhausted developer away from film and to bring fresh developer to film surface. I have made small experiment:
1) glass tank (exactly as Paterson tank);
2) Paterson reels with 120 film (unexposed Across);
4) small tea leaves (will help us to detect layer mixing).
We will rotate reels with different ways and different velocity. We will try to choose convenient way for agitation.
Look at my small report (http://v-and-f.ru/agitaciya-vrashhen...d-iznutri.html).
I was very surprised to conclude that uniform rotation is a worst way to achieve mixing of layers. And powerful rotation (clockwise/counter clockwise) gives us the best results.
I think this information will be helpful for somebody.