It is depending on your nutrient line , some scheduled can be tweaked with many brands like GHE or Advanced nutrients.
My advices in soilless grow would be to stick to a certain Ec/ppm level for each periods like that :
Early veg : 0.5/0.8
Week 2 : 1/1.4
Until End if veg : 1.4
Flowering week 1+2 : 1.5/1.6
Mid Flo : 1.8
End of Flo (+pk boost) : 1.8 / 2.2
You can get higher than 2.2ec but it must descends on the plants needs