Heating a snake rack

I have a custom made 6ft (L) by 3.5ft (H) by 2ft (D) snake rack that has three levels, 4 50L rubs on the bottom two and 4 33L rubs on the top one. My question is, what would the best way to heat this be? My reptile room has an ambient of about 29c. I have tried using a 16m heat cable on a pulse stat but the temps arent high enough (about 31c). Links would be appreciated. Thanks in advance!

Have you looked into Heat Tape such as THG or Flexwat? I use THG to heat my racks and I find it very good and consistent in its abilities to heat the tubs.
BTW, welcome to the forum.

THG Here works great. THG & A HERP stat.