Can you use a 30ml blend in a diffuser?

No, a 30ml blend is not suitable for use in a diffuser. Diffusers are designed for pure, undiluted essential oils, typically using about 2–5 drops per oil. In a pre-made blend, the essential oils are already mixed with a carrier oil, which means they will not disperse properly into the air in the same way as pure essential oils. For diffusing, it is best to use oils specifically intended for diffuser use.