Depeding on how hard (or soft) is your water, you might want to put some cal mag in it. The first week, your aim is to be at 0,5 EC (250 PPM), which is what most people tap water is at. If you are starting with reverse osmosis water (or close to it), this is around 1 cc of cal mag per liter of water.
At the end of the week (beginning of 2nd week) you will need to up it to 0,8 EC (400 PPM) by adding some growth nutes and by week 3, you will want to feed at 1.2 EC to 1.4 EC (600 to 700 PPM). Good luck
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