I like to use Flexwatt or the new heat tape from Reptile Basics. You put the length you need by the foot, the cord, and connectors in your cart and check the box to have them put it together for you. I think it lasts longer, is about the same price even with shipping, and won't have adhesive on it to stick it to the tub if you want to use a 2 tub system. You can use aluminum tape if you want to stick it to the bottom and still be able to move it.