Phytoplankton

[Funky_Fish14]

You know, it really doesnt matter when its 'ready'. You CAN start using it at any time. Phytoplankton naturally occurs/grows in your aquarium, and even if you are dosing a lower density, it still benefits your aquarium. You could also just add more. You can keep a couple cultures going and restart each one every few weeks, just to make sure you dont end up with a crash, but otherwise, you can really use it at any time. And if you mean for storage, who says you have to store a month's worth? Store a few weeks worth, grow some more for a week or two, and then store more.