I do not understand what you mean when you say "keep your soil balanced" or why you think this should be done? Can you clarify?
During veg your plants need food with more N. Check out some commercial vegging nutes and check the N-P-K of those. N encourages good vegetative growth. Light yellow lreaves during veg are often a sign of N deficiency. But your plant does not live by N alone. You will also need a well rounded nutrient or maybe a nutrient line. A lot of commercial nutrients are 2 or 3 part formulas using different ratios of each for different phases of growing.
While the other plants look good, I believe that the leaves curling like that is a result of improper pH. The pH has to be correct or the nutrients will be locked out form the plant. For soil, a pH of about 6.3 to 6.8 is desirable.
Not all plants and strains are going to act like each other with the same environment and nutrient schedule. This is part of what makes it hard to grow differing strains at the same time--each could conceivably demand different nutrient levels.