Lower leaves getting yellow/ burn from tips and goes to uper leaves.

As thse leaves only have 3 blades, I presume they are the lowest leaves, so it looks to me like damage from lying on the substrate during the night and I would not worry about it, the rest of the plant looks happy and healthy. True nutrient "lock out" does not occur unless the pH is below 5.5 or above 7.5. Hope this helps, Organoman.