Joe wrote:
I recently bought myself a pump to use for my winemaking and brewing.
It's mainly because I'm lazy and I'm sick of doing the siphoning
thing. ;-) You can also use filters in it, and while I don't know if
I'll use that option, I'm curious about when you should do it. Is it a
safe bet to think that I probably wouldn't want to use any filters
when moving from primary to secondary? I know that there's some
necessary fermentation that still takes place in the secondary, and I
was worried that I might filter out some of the yeast if I use one
this early in the process.

You are correct about needing to keep the yeast cells when transferring
from primary to secondary fermentation. Filtering them out at that time
will likely cause the fermentation to stick.