Currently doing 4 plants under a 8 bulb 4 ft t5 ho light, adding some leds in flower, currently in veg. This is my 5 t5 grow and once you get it down the results will speak for themselves. Be sure to use the right bulbs in flower most t5 fixtures onky come with blue 6500k veg bulbs. You want 3000k to 2700k bulbs in flower. Imo a scrog with 2 larger plants or 4 smaller plants may be the way to go when using t5 to flower. If i contiune to use t5 i may do it next grow with clones from my current bag seed plants.