ph too high for too long?

I've been watering my plants with my ph too high for to long.(my ph tester was not the most accurate until i got a "REAL" one)I've learned my lesson Although i couldn't see it in the looks of the leaves, but did notice the change in the growth.Could some one confirm this and or, what else can happen when the ph is to high for too long.Other than that, my ph is where it should be now and i can see the change bigger than shit.
Please, any feed back would be great, thanks.

bump, for the crybaby

The sweet spot is around 6.0 to 6.5 on the ph. Your plant will take in all the micro and macro nutrients it needs. If your ph is to high or to low your plant roots will lock-up and not get all it needs.

True for soil; not hydro. Hydro = 5.6 to 5.8.