I had the same problem when I started adding more nutes to my res...the ph would drop initially and then slowly climb...the more nutes the more significant I noticed both of these issues to be...you might be right about the extra waste but the ph should definately level off to a much slower climb...I can't remember how many gal is your res and how many plants you have runnin through?

Once your feeding them full strength half way through flower the climb will definately be quicker so ya might be able to freeze some and dump it in the res in the morning and make fine tuning just at night...

Let me know if ya notice this to be true cause if not it would be good to know it atleast wasn't all of my problem either...so far I'm at 6 weeks and they're not even close to a foot yet but even though I've made tons of mistakes they're still kickin