When to add yeast nutrient?

Hey,

I'm brewing Big Mama's Barley Wine and the recipe calls for 5 teaspoons of yeast nutrient, but it never says when to add it. In the ingredients list it says 4 - 5 days after the primary fermentation has slowed, along with the other additions. I just wanted to make sure this was right because it doesn't actually say in the process. The primary fermentation has already slowed and I plan on adding more sugar, hops, and the Champagne yeast this afternoon. This is were I expected the yeast nutrient to be added. Does anyone know when I should add it? Should I mix it with the water and Champagne yeast?

Thanks

The Wyeast brand yeast nutrient says to add 1/2 tsp per 5 gallons of wort to kettle 10-15 minutes prior to end of boil.

So after the primary fermentation slowed I added more sugar, hops and finally the Champagne yeast along with yeast nutrient. The secondary fermentation started soon after these additions, but has slowed to almost nothing. It's been about 5 days and I'm not sure what to do. The secondary fermentation is supposed to last between 2 and 3 weeks. Should I aerate it again or add more yeast? Any other suggestions?

have you checked gravity?

secondary fermentation in the instructions may just refer to aging the beer in a secondary vessel for 2-3 weeks (i think many do it longer for barleywines) and not necessarily how long active fermentation will last

the only way to know whats going on fermentation wise is to check the gravity