Looks good so far. You will need more and better quality light to get the plants to really grow well tho. Airflow should be alright. It's perfectly normal for the bottom leaves of a new plant to yellow and fall off. These plants will shed leaves as they grow, especially lower branch leaves. They loose them even faster as you approach harvest...all perfectly normal. Learn to read the plants and they will tell you what they need and when they need it! Good Luck!