Lava lamp that is evaporating what do you add?

If a lava lamp is evaporating and the liquid level is low, you can add distilled water to restore the volume. Avoid adding tap water, as it may contain minerals that could affect the lamp's performance. Additionally, if the wax is not moving properly, you can gently warm the lamp to help the wax flow better. However, be cautious not to overheat it, as this can damage the lamp.