How long in primary?

[rekoob]

I have a couple of one gallon jugs of apple cider going, I pitched yeast on 10/19/14.

Air lock activity has slowed and a good yeast cake has formed.

Is it to early to move to secondary?

I was thinking about racking it off and adding more juice to the yeast cake.

Any issues with racking onto a cider yeast cake?

 

[JimRausch]

I'd wait to rack until you've reached the SG you want. Or the visible signs of fermentation are finished, if you aren't doing SGs.
Don't see why you couldn't repitch another cider on a yeast cake. Probably will want to add some yeast nutrient though.