 If you have 10 seconds in a cup of water, you can test how healthy your hair is. Take a strand of clean hair and drop it in a glass of water. If it floats, your hair has low porosity, which means it might be hard for moisture to soak in. If it sinks, it has high porosity, which means it might be damaged, leading to frizziness and fullness. If it sits on top for a second and then slowly sinks, it has medium porosity. This is what you want.