exactly, with the 4 part if you don't want any cal or mag don't add it, with my tap water I need very little cal/mag and very little micro, we all use what works best for us and this shit works for me, V&B worked but not as well as this stuff, with it my buds are looking more like yours and that good imopI dont use cal/mag. Only plant to ever show the need for some was Sdubb.. All I use is PBP grow some bennies and Chito for veg. V$B Dirty for flower. I have some Silica but rarely use it.