add your nutes to your water first and let the water sit for a few before u adjust ur ph...i have a hydro set up and i read to do this in the cannabis bible, ive noticed my after i add the nutes to my water it goes from 7.2 down to 6.3. then i drop my ph and then check it a lil later. so my advise would be get ur water and nutes mixed then wait an hr or so, check ur ph and then adjust