what was your recipe? how old was the yeast? it's unlikely that a 1.053 wort is done at 1.022 but not impossible. did your fermentation area get very cold at some point? adding the extra yeast won't hurt anything though.
three gallons
3 3/4 lbs. pale ale malt
1 1/4 lbs. rye malt
12 ozs. British brown malt
12 ozs. chocolate rye malt
8 ozs. carawheat malt
2 ozs. pale chocolate malt
7/8 oz. home grown goldings
pinch Irish moss
1/8 tsp. nutrient
rice hulls
S-33
mashed at 154 for 45 minutes
The yeast was a couple of months past the best by date, but should have been okay for a three gallon batch. I pitched the yeast at 3 pm and had signs of fermentation by 10 pm and the airlock was burping once a second by morning.
I think I'm going to steer clear of this yeast in the future.
It actually tastes pretty good and doesn't seem like it's at 1.022
The only thing I did different from normal is to use a campden tablet to remove chlorine instead of filtering the water.