Organics are not without their drawbacks, however, especially to the indoor grower. Some organic fertilizers, fish emulsion in particular, have an odor that may offend delicate noses. (However, any security measures involving air filtering or ionization should keep the smell to a minimum.) Also, because organics encourage soil life, there are sometimes more problems with insects, particularly fungus gnats. Finally, organics require a greater investment of time and effort: chemical fertilizers' main advantage is their ease of use.
In the event that you face insect problems, there are a number of organic controls at your disposal. The easiest homemade, all-purpose bug killer is about a teaspoon of soap (I prefer Dr. Bronners Eucalyptus or Peppermint, which are generally eco-friendly and may have additional insecticidal effects) in a spray bottle of water. Spray any bugs you see, the plants (including the undersides of the leaves!) and the soil surface thoroughly with this solution. The soap coats the outsides of the bugs' bodies, which suffocates them.
Another, stronger option is Tobacco tea. The nicotine in tobacco is one of the more potent poisons known, and will generally wipe out even mites, which are usually quite difficult to kill. It's worth remembering that nicotine is poisonous, so keep that in mind. (Unless you also smoke cigarettes, in which case, go crazy.) Here is a recipe:
Buy a package of Chewing Tobacco and put the whole package into 1 gallon of warm water. Let it stand in a warm place overnight 12 hours minimum. Filter the solution using a coffee filter and put it into a clean spray device. You can add 4 tablespoons of dish soap to this and spray the foliage down. Make sure you get the mites. Spray the tops and bottoms of the leaves. Once you have done this sparay the floor and walls in the grow area. Bear in mind that the spray may brown the leaf tips and visible pistils. This is a very powerful contact insecticide.
If you feel like going the store-bought route, a product called Safer Insecticidal Soap has been used with good results. As a final resort, you can use insecticides made from pyrethins, which are synthesized from certain varities of Chrysanthemums. Although they are reportedly non-toxic to humans and animals, they are a potent toxin and probably shouldn't be used anytime near harvest.
With any insecticide, multiple treatments over a 1- to 3-week period will probably be necessary to kill the bugs, plus any new ones that hatch after your first applications.
Finally, perhaps the best route is to go outside and catch some ladybugs (or order them from a nursery or garden supply). Ladybugs are vicious insect killers, but won't touch your plants.