How to make Indigo solution

In a tank of 1000 liters:
a. take 400 litres of water (soft)
b. add setamol ws--> 4 g/l (stirring) ( dispersing solution)
c. Add 100 kg of Indigo ( at 1.8 % shade -see the indigo calculations- stirring)
d. add caustic soda --> stirring ( for solubilising and pH)
e. allow to cool it for 2/3 hours
f. Add hydrosulphide ( As reducing agent)
g. Make the solution to 1000 l by adding water.

If pH is fluctuating, if it is > 11.7 then hydro is added (2-3 kg), if (<11.2) then caustic is added.

For 100 kg of Indigo,
Caustic Required= 90 kg
Hydro Required= 80 kg