the seasons ending homie. if your flowering use some bloom ferts..
And if you can afford it... use Advanced Nutrients. If you cant afford that, Fox Farms. If you cant afford that.. M!$@&$# G#$% ... and if you want free, organic urea nitrate.. piss on it.
Seriously though, look into the Organic section. Bat Guano, Seabird Guano, Blood Meal, Fish Emulsion and whatnot might be up your alley. Allong with a little molasses to feed the micro organisms in the soil.
A nice free additive... Coffee Grounds. NPK 2 - 0.5 - 05 not bad for free. Just ask nice at Starbucks and they will unload 20 - 100 lbs. The worms will go ape shit, and aerate the soil.