t-5s are no where compared 2 pc, t-5s have alot higher par and are a more intencity light. they also last longer, and dont run so hot. t-5s are the closest thing u can get to mh. but it depends on what size tank u have. if its bigger than 125g go with mh because thats when tanks start getting deep. and t-5s only go about 14-18" down, which my can go down to like 24". but if u have a 55, 75, 90g than go with the mh. but over all either one will keep clamd and sps.