Question about fliar feeding nitrozime

Once I've put the nitrozime solution into spray bottly, how long is that fertilizer good before needing to replace?

Im week 6 flowering Sour D-Sour Grape-Blue Widow-Deep Purple (MMM a favorite)

Personally I don't mix anything more than a few hours before I am ready to use, but if you keep it cool and sealed, 3-4 days would be my max.
Just make sure to shake it well before using.

ive been told to let the roots do the work when it comes to nutrient uptake. i would only foliar feed if i was having a problem with my root zone.