New Development today w pictures

Ok today I have leaf tips pointing down and some curling. Yesturday I added some Calmag to the nutrients don't think that would cause it but maybe I'm wrong. Using Cap Ebb & grow. The PH has spiked in the last 24hrs from 5.5 to 6.1 while it had been holding pretty stable. PPM up slightly from yesturday.
Had big growth for the last week and this is the first sign of trouble.

somebody showed me a chart. I wish I knew where it was. it showed the nutrients allowed and locked out due to PH levels. (it was blue and looked like a graph)

bump to the top....

???