Oh and adjust the ph last after adding nutrients also. You will notice a little more overall PH down is used but this will create a much better buffer with less PH drift daily. 0.1-0.2 increase per day is normal. In my coco in veg 5.6-5.8 and a bit higher in flower 5.8-6.0 and like 6.0-6.2.mod flower on. It doesn't need to be exact and res usually lasted me a few days and I just ph to the lowest and let it drift the 0.1 ish a day. If it goes over 6.0 in veg I would readjust it.
I just figured out the drift was that bad. My res lasts about 12-14 days. Checked mid-tank last night and it was like 6.4! Ooops.