My :twocents:

With RO water you loose micronutrients particularly Mg, and Ca. Cal/Mag is a great replacement or the ole Molasses routine.

But you should first repot those if at all possible. I think they are root bound, N overdose which is more because of nute imbalance/lockout with all the K you are giving them. So if it were my plants I would flush them and then repot.