Zara seems to have covered the extra food well, and I'll add in my advice on the bedding^^. Its reccomended, to help controll odor and absorb the urine, to use Yesterdays News. Its actually made for cats, and found in the cat litter section of petstores. It works really well. I like for my ratties to have something more softer to make their bed with, so I either give them some Carefresh, or some shredded computer paper (no ink) to put in their hammock to curl up with.
I don't know anything about juices either... so I'm no help when it comes to that.
I hope I was of any help.