2 Racks, 1 Helix? Help please.

[Jared]

I have 2 racks from RBI..

The 32qt here:

http://www.reptilebasics.com/images/T/t-16197-14.jpeg

and the 12.2 qt here:

http://www.reptilebasics.com/images/P/swide_lg.jpg

Both use Belly heat, I have 1 Helix DBS1000 hooked up to them both.
With the Helix set at 101, the temps are perfect in the 12.2qt rack... BUT the temps in the 32qt rack are about 5 degrees low.

The temp of the actual heat tape in both racks is 101, but it just doesn't increase the temps enough in the 32qt tubs.

Any suggestions or info on what I can/should do?

Thanks!