i use Advanced Nutrients regularly. I wouldnt call pH perfect perfect but if you run it for 7-10 days it should stay reasonably stable especially in DWC. you get into trouble if you dont do a complete bucket change and decide to push your luck. If you run into a problem with a plant using advanced i would just start a fresh reservoir of nutes and that usually takes care of the problem

but i rarely check pH when i mix a batch of nutes (i also dont use full strength)