I would think that if your container was sealed, you are probably fine. The main concerns would be from oxidizing of nutrients, to me... Vitamin C specifically is water soluble, but since you sip on it already all day, I think as long as long as any excess is sealed up tight in the fridge, you'd be fine. Considering a single batch, though, is already 2 quarts, you'd be making a LOT!!! Hope some of this helps.

According to this website, in the comments, someone talks about making it in larger batches and freezing it. Would that be an option for you? https://www.thelaundrymoms.com/the-trim-healthy-mama-singing-canary/

This one looks like a good message board directly with Serene and Pearly where you could ask... (looks like, not verified).
http://trimhealthymama.freeforums.net/thread/2156/singing-canary-pearl-serene

More options so you could mix it up for different days:
http://thetrimrecipebox.blogspot.com/2013/11/serene-and-pearls-all-day-sippers.html

Somebody mentioned that as an option...I think in one of the links I google but didn't past above.? I would think that you could mix everything in with just enough water to emulsify the blend, the add water and blend quickly when making it. Seems like it would work...just from the science side.