confused

so last weekend i brewed up an IPA from a recipe i found online. the liquid yeast never seemed to catch, i didnt do a started because the bottle just said to pitch at 70-75 degrees. its never bubbled in the air lock. i assumed i messed up, needed a started or something. so i hadn't got around to dumping it yet till saturday and i noticed when i opened my bucket, that it looked like it had been fermenting...so i took a gravity reading and sure enough it was lower then my original reading. so i let it be...but can you have fermentation without it bubbling in the air lock?

2nd question...IF this batch isn't completely messed up i'm going to dry hop it. i have an extra sack that i use for my grain and my hops are still in the frig. is it cool to put them in that bag (i dont want to mess with trying to get all the leaf hops out of my carboy). should i boil the bag first before putting it in the carboy (tied to fishing line)? kind of winded there, sorry haha

I've had the mystery fermentation before too. One five gallon pail of a ten gallon batch wasn't bubbling while the other was happily blurping away. I pushed the lid down tighter and away it went. You probably have a leak somewhere. It's easier for the gas to escape through the leak than through the airlock.

I would boil the hops bag first.

Here's what probably happened. Your bucket didn't have a tight seal on the lid, it did ferment and the gas just escaped out the sides of the lid vice the airlock. It's happened before, and it's not an issue.

As for dry-hopping, personally I'd just throw them in the carboy. When you rack, cover the end of your racking tube with a mesh bag/paint strainer to filter out the hops. If you want to keep them in a bag, just soak the bag in sanitizer prior to putting the hops in it. Keep in mind that hops expand like crazy and you might have a hell of a time getting the bag back out of a narroy carboy neck if you put them in a bag.

thanks for the tips! yeah i probably didnt get the lid on tight. i feel a little better now! thanks everyone.