Added water when racking.

Oops.

I think I may have made a boo boo. I noticed that when I was racking that initially hadn't added enough water the first time when sparging to give me a full 5 gallons. So, thinking it's no big deal, I added about 1/2gal of cold fresh water to bring it up to 5gal even.

Now, I have to wait another 2 weeks to finish fermenting, but should I pull the air trap, and use the big hose instead for the first couple days, just in case it starts to foam a bit?

I hope I didn't kill my beer.

Nope, you will be fine. Don't worry about it. Most of the action is now done, and your beer is in the homestretch. It won't suddenly burst into fermentation again.

Ok, I only asked this because I added the water, when normally I wouldn't, and thought maybe a little bacteria from the water may have caused a bit of excess foaming in the second rack. But, it sounds like it should be ok.

Thanks.

Any bacteria in the water was probably killed by the alcohol and the yeast, fermented beer is a very unfriendly inviroment.

That being said, you really don't need to worry about topping off the secondary, all it does is water down you beer, would you add water to your glass if you didn't fill the bottle up enough before capping?

Your beer will be fine, and no actual fermenting is going on at this phase anyway (at least it shouldn't be). RDWHAHB.