question about primary time

Just trying to avoid bottle bombs here. Its been 7 days since i first started my 6 gallons of hard cider in the primary glass carboy. The first 5 days the airlock was gurgling about 2 times every second, and is now about 1 gurgle every 20 seconds. I added 3 lbs of brown sugar to the batch plus champagne yeast and some nutrient for the yeast. My SG was 1.082 or 11% ABV when i first started. What should it be when the yeast is done fermenting? Just wondering if I should keep waiting the 2 weeks before using the secondary or if I should watch for when the gurgles are a minute apart then rack into the secondary? I hear a lot of different guidelines on using a hydrometer to check when fermentation is done. Is there a textbook answer?

yes the textbook answer is to check with your hydrometer...... using the champagne yeast it should ferment to .999 or so, at there point there will be no sugars left and no chance of bottle bombs. If you want to have a sparkling cider you'll have to add some priming sugar when you bottle

It depends on your yeast. I skip the secondary all together and let it sit on the cake for 6 months, its much less work less chance for infection, and the cake itself tastes great.

That would be a lot easier. I keep reading about how the air is so bad for cider. But it is exposed to air when you siphon between primary and secondary. I checked the gravity yesterday and its near 1.000 I am guessing that its just about done. 7 days seems fast to me. I must have had hungry yeast.