the top leaves are lush green with new growth, but on the bottom they are still curled at the tips and 1 plant has burn (brown) tips, the leaves have a slight yellowing (really just less green) on 1 as well. And the first set of leaves as still twisted. Now like i've said i've readjusted the ph, added another 2 liters of water this morning, how long would it be before i'd notice a change and is this nute burn?