What causes this on my leaves?

If one of your cannabis plants is exhibiting different watering requirements and is not as thirsty as the others, it could indicate a couple of potential issues. Here are some possibilities to consider: Root Health: Uneven watering needs among your plants might be a sign of differences in root health. The plant that is less thirsty could have healthier, more efficient roots that can absorb water and nutrients more effectively. Conversely, the other plants may have root issues or restrictions that affect their ability to take up water. Overwatering: While you mention that you provide the same amount of water to all your plants, it's possible that the plant with lower watering needs is experiencing signs of overwatering, which can lead to slower growth and reduced water uptake. Make sure that you're not consistently keeping the soil too wet, as this can suffocate the roots and lead to nutrient uptake issues. Nutrient Imbalance: Differences in nutrient requirements among plants of the same strain can occur due to variations in their individual genetics or environmental conditions. It's possible that the plant with lower watering needs is also more efficient at nutrient uptake, which could explain its reduced thirst. To address this issue, here are some steps you can take: Check the Roots: Gently inspect the roots of all your plants. Look for signs of root rot, root-bound conditions, or any other abnormalities that might be affecting water uptake. Adjust Watering: Water your plants based on their individual needs rather than a one-size-fits-all approach. Ensure that you allow the soil to dry slightly between watering sessions. Nutrient Levels: Monitor the nutrient levels in your soil or growing medium. It's possible that the plant with lower watering needs is more efficient at nutrient uptake. Adjust your nutrient regimen accordingly. Light and Environment: Ensure that all the plants receive the same amount of light, temperature, and humidity. Variations in these environmental factors can also affect water uptake. Observe and Adapt: Continue to closely monitor your plants and adjust your care routines as needed. Plants can exhibit different behaviors, even within the same strain, so flexibility and observation are key to successful cultivation. By addressing these factors, you should be able to better understand why one of your plants has different watering needs and take appropriate action to promote healthy growth for all of them.