PH

As long as you use bottled water and pH balanced nutrients then you have nothing to worry about since bottled water usually comes in the 6.0-7.0 neutral range. Later through the grow using bottled water will be to costly so I suggested a few other options on a different question of yours hopefully that helps! When you switch from bottled water to a different source then do check the pH before every irrigation (if you have a reservoir then you only need to check when it is filled) Good luck and happy growing :)