That's good to know. It just doesn't make sense. If it leaches out ammonia and other bad things just soak and wash several times before use, why do a 100 percent water change? It is a waste of time an money. Just trying to understand the logic behind this.I've never done the recommended water changes during the 'cycle' process. I only swap water when ammonia concentrations exceed 5-6PPM. And even then, it's usually only a partial change.