Peter wrote:

That is the volume of developer required to cover the reels.
You need that much developer as a minimum.

I can understand that, things I do not understand are those divide
symbal and numbers after them. I also do not understand the "1x127",
is it a film format?

if you do this,
make sure that the reel has no tendency to ride up on the centre
column, if the film rides above the developer there will be a
problem.

Thanks. I found there is a plastic lock which can lock the reel firmly
down.

Inversion agitation tends to work better than swizzle stick
agitation.

If I rotate the rod fully a circle, is it still worse than the
inversion? In my test with the cover and eyes open, I can not find a
reason why the inversion is better in the case. Maybe I i'v ignored
something, would like to tell me the story inside? A lot thanks!

-
narke