Cost of Foliage-Pro vs. Bag of Water Soluble
I read many discussions here recommending Foliage-Pro as a fertilizer. While I have not used it, apparently it is a good 9-3-6 liquid. I would like to point out that by using a bag of water soluble fertilizer, you can lower your costs to less than a tenth of the cost of F-P.
Using Al's recommended rate of 1/4 teaspoon F-P in a gallon of water for each watering, this amounts to 30 ppm of N. At $42/gallon of F-P (current online price), this is 1.4 cents per gallon of mixed fertilizer.
If you purchase a 25 lb. bag of 24-8-16 (I use Plantex Foliage purchased at BFG) for $35, your cost per gallon at Al's rate is now .13 cents. While Plantex Foliage does not have Ca or Mg, many growers have plenty of these elements in their water supply.
Some growers may prefer pre-mixed fertilizer. I use a lot, and am willing to mix my own to save money.