SUBSTRATES

Fertilizer isn't your limiting factors. Carbon dioxide is. As far as a good fertilizer, use something like a 3-part system - J.R. Peters (Jack's) is one. I've even used it in soil with great results, although it's listed as a hydroponic fertilizer. Provides everything and it's cheaper per gallon if you buy the 25-lbs bags (something like $0.04 gallon including an 8lbs cheap bag of foodgrade walmart epsom salt) Can't beat pennies per gallon. Your lights and carbon dioxide are what the plants need to power growth. Dumping more ferts into your substrate will not grow a bigger plant unless you were starving it before. you should think of providing optimal amounts, not maximum amounts. Back to lights- - without co2, you don't need to provide more than ~800-1100 par or you are damaging your plants. With increased CO2 ppm, you can go higher.. think 1500par? Want to grow monsters? Buy expensive and efficient lighting so it doesn't cost so much per month. Buy a co2 emitter of some sort - if you run the numbers on the yeast /sugar water home remedy it's not feasible and doesn't save money due to quantities needed. Get a tank.. and learn soem safety measures so you don't die of CO2 poisoning or asphyxia or whatever it's called, lol. Otherwise, provid elight upto ~1000par relative to your square footage and give what it needs, not too much.