Nutes ph in hydro grow

Growing plants in a hydro, active drip system. I start the nutes out at 5.8 ph, but by the end of the day it is close to 8.0. They continue to use a lot of water and grow quite well even though this is way too high according to everything I've read. Taking the ph before lights on after setting all night, the ph is still usually 7.25.
I average two to three ounces of bud per plant, on 2 foot plants.
Would I have better results if I adjust the ph every morning before lights on, or just leave well enough alone?
Is this normal for the ph to spike?

Im running a 11 pot recirculating drip system and I set my PH at 5.8 and it will run up to 6.6 at the higest but never in the 7's or 8's .. is this in veg or flower?? If its in flower its probably because you need bigger pots.

What kind of water do you use to mix your nutes?
Which nutes are you using and how much?
Have you calibrated your pH meter this week?