Ph-ed water storage

Hello eveyone!
I've done some searching but am probably using the wrong words...
I have (9) seedlings started and was just wondering how long pre-mixed Ph-ed water will last?
Can I mix up a couple gallons and store it for a bit while I use it, or should I only mix up what I plan to use? It will be water only for right now... no nutes added yet...
Thank you!

Better to ph what you're going to use I.wouldn't store it.

Ph as you use. Not sure how your water is but mine is pretty hard and high alk so in 12 hrs it turns alk again. So thats why I recommend phing as you use

Perfect! Thank you!