Welcome to the world of PPS.
Yes there are various solution depending on the approach. The three main approaches are descibed here:
http://www.aquaticplantcentral.com/f...s-summary.html
PPS-Pro is the easiest. Especially for newbies like me.
The mixes keep for a long time and do not need to be refrigerated. I would not mix more than 1 batch at a time, but other than that you will be fine. The dry chemical last a long time.
Anymore question, just let us know.