i've never used irish moss before. stuff coagulates and settles during the cold break as your wort cools from the boil.
just let it be in the primary for a week or so. then rack it to the secondary being very careful not to stirr up what has settled. leave all that trub/yeast/hop sediment behind.
same goes for the secondary. once you've transfered it, just let it be for a spell, 3-4 weeks in the secondary will let alot of particles settle. be careful not to stir it up when you rack to the bottling bucket or keg.