Money Tree (Pachira) with a Rotten Trunk: What to Do

Normal for Braided Specimens

It's common for one or two of the braided trunks to die. It's not a disease and won't spread to healthy trunks.

Action

• Cut the dead trunk off at the base for appearance.
• Or leave it—it won't harm the others.

Ongoing Care

• Bright indirect light.
• Water when top quarter of soil is dry.
• Prune taller stems occasionally to prevent legginess.

Your watering (weekly with drainage) sounds appropriate. The remaining trunks should continue to thrive.