yellow leaves is not a sign of nutrient burn for starters, and while it could be caused by several things from a deficiency or ph problems or lack of light.
would probably keep feeding them atleast every other watering and chances are they may very well come out of it, if its a simple nitrogen deficiency, but it might be a good idea to find out the ph of your soil and maybe try a better brand of fertilizer just incase you continue to have problems.