When would one use LECA and not charcoal and vice versa? To my knowledge, both are similar in that they do not break down and they allow good aeration to the roots. I would think LECA would retain more water due to its smaller size, as compared to charcoal chunks. How does it compare to charcoal chips and is there any advantage/disadvantage to using LECA rather than charcoal? Charcoal is definitely more cost effective though.