Answer

In Jain Dharma, singoda / water chestnut is generally avoided by many Jains, because it is considered an underground or water-root type food and its harvesting may involve significant harm to living beings.

Explanation

Jain food discipline is based on Ahimsa — minimizing harm to living beings.

Water chestnut grows in muddy water and is obtained from below the surface. Because of this:

• It may involve disturbance of many small water-bodied and earth-bodied living beings.
• It is often treated similarly to root/underground foods by many Jain families and traditions.
• Therefore, many Jains do not eat singoda, including singoda flour.

However, practices can vary slightly by family, sect, and local tradition, especially during fasting foods.

Takeaway

If you follow strict Jain dietary rules, it is better to avoid singoda / water chestnut. If your family or guru has a specific tradition, follow their guidance respectfully.