I wish I had a local hydro store... 8-( I use general hydroponics along with several other different additives. Most importantly for the Aero Garden is Hygrozyme which helps keep your res clean and roots working effecienty, I also use sweet carbo citrus, liquid karma, and cal-mag in my res water. Thats just what I use you dont have to do what I do, everyone develops their own concauction over time.