@McDee
FYI > with Mega Crop one part and ProMix HP I start watering with it right from the start in the solo cup, 1/2 of the recommended amount on the schedule on the Green Leaf site.
I kind of followed the age chart amounts fed And watch the color of the leaves. When I notice slight yellowing on the bottom leaves I up the feed by .5g/4L.
Through the grow I was roughly at their recommended amounts but two weeks before harvest I was at 7.5g/4L...
Well water and MH/HPS so no additional cal mag..
I did not notice any significant differences between the plants fed with General Hydroponics MaxiGro/Bloom and the ones fed Mega Crop, either in amounts fed or performance.
Cheers