Pothos leaves turning yellow is typically a sign of stress in the plant, most commonly caused by issues related to watering, light, temperature, or nutrients. The main reasons include:

• Overwatering: Too much water can cause root rot, making it hard for the plant to absorb nutrients, leading to yellow leaves and sometimes black stems or leaf tips.
• Underwatering: If the soil is too dry, leaves can yellow and wilt as the plant conserves water.
• Light issues: Pothos prefer bright, indirect light. Too little light can cause yellowing, while too much direct sunlight can burn and yellow the leaves.
• Temperature stress: Pothos like warm temperatures (70-90°F or 21-32°C). Colder temperatures can cause yellowing and leaf drop.
• Nutrient deficiencies: Lack of nitrogen, magnesium, iron, or potassium can cause various patterns of yellowing in older or younger leaves.
• Natural aging: Older leaves naturally yellow and drop as part of the plant's growth cycle.

To fix yellow leaves on pothos:

• Adjust watering to let the top 1-2 inches of soil dry between waterings.
• Provide bright, indirect light avoiding direct sun.
• Maintain stable, warm temperatures.
• Fertilize during the growing season with a balanced plant fertilizer.
• Remove yellow leaves to encourage new growth.

These guidelines will help determine and address the specific cause of yellowing leaves for a healthier pothos plant.