Water is never the best medium to root a cutting.

I would get it out of the water, rinse it off really well. Cut off anything thats mushy. Get some powdered rooting hormone (Rootone is usually available at home depo, lowes etc. that has a fungicide in it) Dust the cut parts in the hormone. Put it in potting soil with a lot of perlite added. Place it in a smaller pot with good drainage holes. Put it under a plant light. Keep it well watered but dont let the pot sit in water.

Catarina - you are trying to propagate by way of STEM cuttings, as opposed to removing a leaf and putting the petiole (leaf stem) in a container of water - yes? I only ask because these plants come very easy in a solid medium from stem cuttings.

Al

Yes it is a stem cutting :(
I have since followed the advice of getting it out of the water, rinsing the stem and node off and planting it in soil. I hope it survives.

As do I (hope it survives). Best luck.

Al