Newb question on airlock

[Nate1977]

Hello all.

After reading about homebrewing for years and somehow never getting around to doing it, I just got my first batch (Anchor Steam clone) in the primary. I assumed I knew exactly what I was doing until the final part.

I have a 3 piece airlock of this type: http://www.midwestsupplies.com/products/ProdByID.aspx?ProdID=4216

My question is this: do I leave the cap on the airlock? That would seem counter intuitive to me. I figure the gas needs a way to escape. And why would it come with a cap? However, once I thought about it I always seem to see pictures with that airlock cap on. So... on or off?

Also, is water ok to use as the fluid inside? I've read some people insist on sanitizer solution or vodka.

Thanks! I appreciate the advice.

 

[Ryanh1801]

Cap stays on it has holes on the top. I like using cheap vodka. I would not use regular water because some will get sucked in, so you want it to be sanitized.

 

[Kayos]

Sanitized, water or vodka. Fill about an inch up. The top thingy will float and bob with the fermentation.

 

[Nate1977]

There are holes in there! I'm apparently blind. I emptied out the water and put in some vodka.

Thanks all!

 

[Rook]

crap I forgot to buy vodka today. I doubt the liqour stores are even open on sunday (curse you washington state liqour laws!). SWMBO won't let me use any more of her kettle one.