The Flourish comprehensive is really kind of worthless imo. And if you bought your plants from a local store, sometimes they will tell you anything if they are needing to push some older plants before they are not sellable. Do all your research before you head to the store. Like for instance, go browse around and any plant you dont recognize just write em down or whip your blackberry out.... (seems like im the only person who doesnt own one) and google it. Also dry fertilizers are way cheaper. I recently bought a pound of each - nitrates, potassium, phosphate, and trace mix for 23 dollars shipped. And a sandwich bag of nitrates will last you almost untill death on a small aquarium. This way you can add what you need, not what the bottle says. Or you can also look up local hydroponics stores and talk shop with them as well.