Decanting

Decanting is where you turn any type of Potion with a dose of 3 or under and add in another dose. for example, you have 4 prayer potion each with a dose of 3. you decant the potions into 3 prayer potions each with doses of 4 and an extra vial.

Some players use decanting as a way to make money. They buy potions with doses of 3 in big loads like 1,000 in the grand exchange. They decant them and sell the potions for highest on the grand exchange. Players can right-click on Bob Barter to automatically decant potions for you.