31 Aug. I start the third week of my autoflower. The plant is growing well, but I noticed small yellow spots on the leaf tips, which seem like a mild calcium deficiency. This is probably due to the fact that so far I have been giving water with a slightly low pH, around 6, while the ideal range would be 6.5–7. At the beginning, to lower the ppm of the tap water (which was around 211 ppm), I mixed it with demineralized water. This brought the ppm down to about 109–140, making it harder for the plant to absorb the available calcium. Additionally, the soil I am using, Biobizz Light Mix, is lightly fertilized but does not contain enough calcium to correct this small initial deficiency. For this week, I will not add any fertilizers. I simply want to raise the pH to 6.5 and use water with higher ppm, so the plant can better absorb the nutrients already present in the soil. The lamp is positioned about 35–36 cm from the plant and so far there are no burn issues. Temperatures range between 25 and 30 °C depending on the day, while humidity in the room stays between 40–60%. The humidifier is always on because I keep the window open, but the dehumidifier is not being used, as it is not necessary at the moment. I also have a new oscillating fan arriving to replace the current fixed one, and I’m waiting for a regulable extractor (90–145 m³/h), which will allow me to control the air perfectly during winter if needed. This week my main goals are: Increase the water ppm without overdoing it Adjust the pH to 6.5 Keep observing the plant without adding any fertilizers Everything else seems fine and growth is regular. With these corrections, I expect the new leaves to grow healthy and free of spots. ==UPDATE 31/08== To control the calcium deficiency, I will administer an eggshell solution until I reach 300 ppm (I will boil some eggshells and administer the solution in tap water). ==Update 4 Sept== By mistake, I adjusted the pH twice, once to 7 and once to 8, and obviously the plant immediately showed symptoms of incorrect pH. At the next watering, I'll give Biobizz Grow with a little Biobizz Bloom since the plant has entered pre-flowering. I'll adjust everything to a pH of 6-7 and a ppm of 450-500.