When I am consulting, I get asked for a complete but cheap nutrient lineup that is suitable for commercial usage. This lineup can also be scaled for the home grower to save some serious cash.
You start with a salt base nutrient. Jack's classic hydro, Masterblend, Jack's Nutrients TAP or Growmore soluble powders also work depending on your access.
Jack’s Hydro Feed- 25 lb bag
$70- 2000 gallons
Add your biostimulant. Mr. Fulvic is the home and garden version and has fulvic, amino and organic acids, chelated micros and trace elements. AGT-50 is the commercial wholesale version. They both help make nutrients available regardless of pH and give salts organic taste and smell.
$460- 20,000 gallons
Extra calcium is needed at transition. Growmore Flowering Cal-Mag also has kelp to help stack nodes going into flower. Albion metalosate and epsom salt can also be used.
Growmore flowering cal-mag- 2.5 gal
$90- 1900 gallons
PH down is pH control, but also adds soluble phosphorus when something like HydroFeed is low in Phosphorus.
Advanced pH down- 4L
$82- 6600 gallons
For IPM, insecticidal soap will take care of bugs and mold.
DES-X Insecticidal Soap- 2.5 g
$85- 300 gallons (@1%)
For a bloom booster, Monopotassium phosphate used weeks 4-6 of flower.
Haifa MKP- 4 lb
$20- 1820 gallons
This is a complete lineup including IPM. It can be used large or small. There's no reason to spend a ton of money on fertilizer for excellent quality cannabis.