I don't know how long of a piece you plan on using, but the longer the strip the more of a temperature difference you can get from the beginning of the run to the end. To get more accurate temps shorter lengths are advised. I just finished a hatchling rack that holds 36 tubs (4' long and 34" tall) 6 tubs across and 6 shelves. I am running individual pieces to each shelf. What is also nice about this is I can just plug in the shelves I am using at the moment and not waste elctricity on the rest.