How many T5 lights do I need for veg is one question most growers ask themselves. Veg is the vegetative period in a plant’s growth and during this period, they require optimal light to flourish. If you’re making use of a T5 light, you may want to know how many light bulbs to use during the veg period. This is why we will be discussing how many T5 lights do I need for veg growth. So, continue reading to learn about this.