um.... i try to buy small bottles, ive noticed that some nutes will rot or end up with some penecillin type looking mold floating around in it.
pre mixing nutes is good, but dont do that for more than what your going to use in 1 day. adding acids to bases will end up nutralizing the 2 (sounds good right?), but it also creates salts as a byproduct.
if your using an aerogarden, id imagine its the same as any other DWC type set up, where theres a MAX amount of water (right under where the roots are) and a MIN amount of water (right above the top of the water pump). now if your adding water, to the max line, and by the end of the day, your under the MIN line, then that shit sucks, and you need to go get a nice DIY system. i recall that my DWC reservoir held enough water that adding more didnt have to happen more then once a week.
its up to you, but more water capacity means less work, as well as having a bit of a buffer in case you go heavy on some nutrient, or whatever
