I think you may be better using tap water that is unfiltered. Tap water usually contains Mg and Ca that are beneficial to plants and your filter will remove these. You then have to use a micronutrient that has them in. In soil you wanna try and get your ph down to 6.7 for the best nutrient availability. A tip - Don't use malt vinegar to PH your tap water. It changes the ph but over a few days your ph will rise up to whatever it was in the first place. Get some Ph up from the grow shop (Phosphoric acid) or try using Real vinegar (Acetic acid)