Feeding by the millilitre on a bottle label ignores what your water already contains, which in hard tap areas can be a third of the total before you add anything. An EC or TDS pen removes the guesswork for a few pounds, and the feeding notes on https://kushindicaseeds.com give target ranges by growth stage rather than fixed doses. Compact indicas generally want less than the chart suggests. Reading runoff tells you whether salts are building up in the medium.