I got it fixed staying at 5.9ph now thanx all for input
You are absolutely correct @sillyman
i have dwc and i dont have any issues but i dont use the silica it will drive up your ph. i use genral hydroponics and add a bud boost in the buding cycle. alsoi change my water every 2 weeks. it works for me. but everyones water is differant.
Careful with some bud agents. They may contain sugars or organics that are not compatible with DWC.