Are you talking about at the same time or storing it for later use?
If it's right away, yes, you can use it...The powdered stuff though won't store after mixed...
The only true no-rinse ones that are fda approved Star san and iodophor you can store with distilled water for quite awhile...
I would seriously consider switching from that powdered stuff when you run out..It really isn't an FDA approved sanitizer (it reads a gray area, that frankly I won't risk my time and money by treading.)
Read this thread I explain what I'm talking about, as well as provide info to help you choose the RIGHT sanitizer...
http://www.homebrewtalk.com/f39/sanitizer-question-54932/?highlight=sanitizer+question
