Jim:

I'm a kit kind of guy, and I tend to use the additives included in the
kits, and that includes clearing agents. The popular one in Canada is
Kieselsol-Chitosan. Good grades of gelatin were apparently difficult
to source during the Mad Cow thing. Don't know about now. Don't know
if K-C or K-G is better or if it depends on the circumstances.

I tend to use a combination of gravity and clearing agents. I bottled
a kit today, so have the data in front of me.

Nov 5 - started - sg 1.084
Nov 16 - to carboy - sg .990 (ferment complete)
Dec 13 - stabilizers and clearing (isinglass) added - .988
Jan 24 - racked off sediment
Feb 9 - filtered and bottled

That was a six week kit, and it took me three months (13 weeks or
so). That was actually quick for me, because we're low on wine.

As you can see, I did not add the clearing agent as soon as the
ferment was finished.

Steve