I have always allowed the reservoir to backfill with the beer that I am filtering. After sanitizing the filter, purge it with CO2, then backfill with unfiltered beer. It eliminates the problem of dissolved oxygen being added to the beer! Just make sure that you don't start recircing the filter full of unfiltered beer until after you have the slurry prepared. I always backfill the entire filter with beer, prepare the precoat slurry in the reservoir, then start circulating the filter. This distributes the initial yeast load throughout the precoat layer. By the time you have finished the precoat, the filter will be filled with bright beer, and you are ready to roll.
It has worked well for me for many years.
Last edited by mlabbe; 03-12-2006 at 04:41 PM.
Brewery Engineer / Brewmaster
Aeronaut Brewing Company
Somerville, MA 02143