While it looks like it's off topic, this is from another discussion of Antoine's problem that is being moved here.
Bone Meal is an organic fertilizer commonly available at garden and hydro stores. A 3lb box can cost as little as 5$ so it's pretty cheap. It also comes in large 20+ pound bags which usually costs half as much per pound. Most Guanos would also work well to fix your plants and can supply more N than the Bone Meal but are more expensive.
When solid fertilizers like Bone Meal and Guano are mixed into the soil, they slowly release some of their nutrients each time you water and will last awhile. Making them into teas turns that time release into instant release. This gives the plants more nutrients at once and can burn them more easily, so much less is used than when mixing them into the soil. Teas are made by taking solid fertilizers and soaking them in water for 1-2 days, depending on the process being used. The solids are then filtered out and you are left with a liquid containing all of the nutrients.
We use a little heat, just enough that the pot isn't really steaming, as well as frequent stirring to speed up the process. We'll put the covered pot on the stove for 6-8hrs with stirring, then turn the heat off and go to bed, letting the pot cool overnight. The next morning, I'll put it in the fridge for an hour or two until it's cold and then filter the solution through a piece of old, high-threadcount sheet fabric. It works well as a filter, getting most of the crap out without clogging easily, and they're washable. When the solution is cold, it can be filtered more cleanly because more crap will fall out of the liquid as it cools. There are threads on tea making in the Organics section.