I use the Alaska brand fish stuff. This was discussed on another thread I think. It is fish based, but not truly organic. It is deodorized, which I appreciate! As I have mostly herbs am selective. There are now about 150 containers and some in-ground herbs & flowers. Most of the herbs do better with lean soil, which means they don't grow real fast! My one exception is basil. I try to fish that 1/week, and sometimes hit the chives and tarragon to urge growing. The rest I do about 1/month.
I mix approx 1/2 cup in a 5 gal bucket of water, and dip that onto the plants with a large plastic folgers coffee can.