narke wrote:
I got a AP develop tank, I feel that's very good. But I still have two
question about it.

1) There is a table as below marked on the bottom of the tank, and I do
not fully understand its meaning. Can anyone explain that for me?

1 x 135 / 126 = 375cc
2 x 135 / 126 = 650cc
1 x 127 / = 490cc
1 x 120 / 220 = 590cc

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

2) After a test, I found 375cc solution can submerge one reel, and
650cc can submerge two. My 2nd question is, can I use only 375cc
solution for the processing?

Yes you can. Many people are happier placing a second empty reel
above their loaded reel and filling the tank as if for both reels.
I tend to do this, but the manufacturers of plastic tanks have
been suggesting partially filled tanks (at least for developer)
in their instructions for years, and if there were serious problems
they would have stopped recommending it by now. 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.

be a reason that AP mark a 375cc in its tank. Actually, since the tank
provides a rod (on the center top of the cover) to stir the solution,
so I never need to shake the tank by invert it. Hence I believe there
is NO change the film will exposed to the air in the stage of
agitation.

Inversion agitation tends to work better than swizzle stick agitation.
Don't worry about the air in the tank. The film is sitting in the
developer for all but a few seconds each minute. Agitation should
be a lot gentler than the name suggests, the purpose is to make
sure that the tired developer at the surface of the film is replaced
by fresh developer once a minute (or every 30 seconds with the
Kodak method).

Peter.
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