How many roll film tanks?

Hello All,

I have been studying Ansel Adams' three excellent photography books
and trying to plan some things for a darkroom I am building. I was
reading the "Roll Film Processing" section in "The Negative". Most
places online indicate that one tank is used and chemicals are dumped
out and replaced by the chemicals in the next step. Ansel's
instructions seem to indicate a separate processing tank for each
step. I think this is further clarified by the pictures in which each
tank has a different letter on the front. I counted five as follows:

1. Pre-soak
2. Developer
3. Stop Bath
4. Fixer
5. Hypo clearing agent

Being new at this I am trying to stay as true to Ansel's
instructions/technique as possible as a starting point. I figure if I
follow the instructions of one of the masters it will eliminate a lot
of initial frustration. What are all of you doing? One tank or
separate tanks? Anyone tried both and noticed a difference? It seems
like chemical residue in the single tank scenario could play a part in
affecting development.