The bigger the ratio to the water, the longer the fermentation.
Honestly, I think 7 days at room temperature is far from being enough, even at normal ratios.
What I'm doing for my latest batch is this: 6 tbs of molasses, 10 tbs of EM, the rest is filtered water. Brewed 5 days and a half at about ~35-45 Celsius degrees, and it keeps brewing when I start consuming it.
You can play with adding stuff to the EM but many stuff will buffer the acids and make the fermentation longer.