What is the primary use for Irish Moss and where does it fit into the process?

MasterB - Here you go:

Clarifying agent. A dried form of marine algae.
It causes haze-forming substances to coagulate and settle out.

USAGE:
Add 1 teaspoon per 5 gallons to the wort in the last 20-30 minutes of the boiling process

It is used for clearing your beer. Without it I have seen cloudy results, which turns off non-hombrew drinkers a bit. Drop in a teaspoon full at 15 min. left in the boil.

Another option is Whirfloc tablets. Different stuff (I think), same purpose. The fact that they're in tablet form means no measuring, which is nice. Just one tablet per 5-gallons.

Awesome, thanks for the feedback. I will definitely implement Irish Moss into my next Pale Ale.

Whirl floc I believe is Irish Moss, just in a different form. Super easy.

Whirfloc is Irish Moss and some other nutrients/chemicals.

I love Irish Moss I toss it in the last 15 and will never brew with out it again the only batch I did not use it in took 6 weeks to clear and still had wicked chill haze.. When I use it I get clear beer with in 3-4 weeks and little if any chill haze..

This may be a stupid question but does it matter whether I put the Irish Moss in a steep bag or not? I would assume I use the bag but wanted to make sure.

Even when I use a hop sack I put the Irish Moss in the wort not the hop sack.

I do exactly what cdrsfrg does. I do hydrate it first, but that's to make it easy on my pump should some be sucked through it.

I've never bothered to hydrate the IM... I run the pump the last 10 minutes and occasionally for a minute during the boil.

so your thinking the IM is falling down and going right out the dip tube.. wouldn't the boil action sort of prevent this from happening immediately while still hard?

You'd think, but the one time I added it without hydration, my pump made some very strange noises. For what those things cost, I'll hydrate and not chance it.