I know when I went to bloom stage my plants took a big jump and needed some fair increase in their ppms but I also changed over to bloom nutes at the same time. They do alot of growing at this stage so I'm wondering...but I'm not sure because I'm just not familiar with the Vita Link nute....the ph going off can certainly cause an issue.....did the plants have none of that yellowing before that?

If your ppms are dropping then you need more....the plants are eating it....sounds pretty much like what I experienced when going to 12/12.