To fix etiolation in cacti, you need to provide the plant with adequate light and make adjustments to other environmental factors. Here are the steps to fix etiolation: 1. Increase the cactus's exposure to direct sunlight or adjust the position of grow lights to provide the necessary light intensity and spectrum. 2. Enhance air circulation around the cactus by placing fans or ensuring gentle airflow. 3. Adjust your watering routine to prevent overwatering and provide well-draining soil conditions. Feed the cactus with a balanced cactus fertilizer to address any nutrient deficiencies.