Provide fresh water for those propagating in water on a weekly basis as algae develops. If there’s no algae in the vessel you can feel free to just top off the vessel with fresh water to ensure the rooting part of the stem is submerged.
Can my plant live in water indefinitely? Most aroids have evolved in an environment that allows it. These plants originate from ancestors that lived in swamps, so being able to adapt to flooding conditions and still being able to grow was a key to survival. As a result, the descendants of that ancestor have the ability to grow in water indefinitely, too. However, they are still land plants and will grow better if planted in soil for a long period of time.
High humidity for rooting mixture: A humidifier or plastic bag secured over the cutting can help to boost humidity until the plant is rooted. To check if the plant has rooted, tug on the stem gently to see if there is any resistance.
Rooting hormone: Less is more! Wet the tip of your stem, dip it in the rooting hormone, shake off excess powder, and then plant.