Ph and coco

[Steveo h]

When I say newbie , this is my second indoor grow. My first I account mostly to experimentation and man did I learn a lot. I'm brand new to coco and to make a long story short........... why does my ph drop so hard when I'm doing water feed feed water? I'm using GH lucas formula 6-9 ??? Filtered tap water is 97 ppm. Assuming I'm doin everything else right...... why ?

 

[St.buds]

You should pH your water at 6 in coco I would flush the plants then start feeding Normal keep tht water pH at 6 and you should be good