[sunmiztres]

I have been doing the EI method for quite sometime and I have pressuirized co2. My co2 is running about 35. All my plants seem to be growing good but I am having problems with the leaves looking not good at all. They look "cracky" they are not actually cracking but have that look to them. Also on some of my plants the leaf edges bend inward. I have no clue what fert I am lacking since I AM DOSING THE EI method to a tee. Any suggestions what might be causing this?
Thanks