My avocado plant which I had germinated with the toothpick and water method has a root shooting from the bottom. It was white and growing quickly. I had decided to (my stupid self) add some fertilizer to the water, thinking that it would help the avocado grow by giving it nutrients. Sadly the root has gone brown and stopped growing. Is my avocado dying? If so how do I keep it alive? I have thrown the fertilized water out and replaced it with just normal tap water again.