would try using epsom salt to eliminate the possibility of mg defficiency it can cause yellowing and upward leaf curl just mix a teaspoon in a gallon of water and feed the plants with it.
ph is important and if you have no idea where its at it could be causing your problems some nutrients may be available but if the ph is out of range they will not be used by the plant, in soil you want it slightly acidic around 6.5.
your pots are a little small also for a 3 month old plant you should consider 3 gallon pots or even larger.
yellowing leaves is not normal, it is a common mistake to think that yellowing is normal during flowering but with the right nutrients on an indoor grow where temps dont really come into play, the plant should still be very healthy green even at harvest time if its yellowing your not giving it the nutrients it needs so its forced to pull them from the leaves instead which can hurt yield.