Artful Intelligence.
Compared to conventional Estimative Index fertilisers:
2X more nitrate limiting for richer colours*
2X more magnesium for stronger growth^
Dose 2ml per 100L daily
200ml lasts ~3mths for a 30 Gal / 115L tank. Pump not included. 
- why + 
*in terms of the relative amount of nitrogen vs other nutrients per ml. 
 ^in terms of the amount of magnesium per ml.The EI approach pioneered by Tom Barr is designed to provide a unlimited / unconstrained amount of nutrients to plants based on a professionally Estimated Index of their needs. APTe provides a calibrated version for richer coloration and algae control. 
 FAQ Here.
- ingredients - 
APT E / Estimative Index 
 Liquid inorganic macronutrient fertiliser
 NPK (Mg) fertiliser with micronutrients and trace amounts of Boron (B), Copper(Cu), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn).
 1.6-1.7-8.5 (+1.6)
 1.6% Total Nitrogen (N)
 - 1.6% nitric nitrogen
 1.7% Total Phosphorus pentoxide (P2O5)
 8.5% Total Potassium oxide (K2O)
 1.6% Magnesium oxide (MgO)
 0.18% Total Iron chelated by EDTA, DTPA and EDDHA.
 All nutrients are completely water soluble.
 Ingredients:
 Potassium sulphate (CMC1 CAS n°7778-80-5) Potassium chloride (CMC1 CAS n°7447-40-7) Magnesium nitrate (CMC1 CAS n°10377-60-3) Magnesium sulphate (CMC1 CAS n°7487-88-9) Potassium phosphate (CMC1 CAS n°7778-77-0)
 
        
 
            
                        
           
           
           
           
           
           
             
           
             
           
            