PC question

[Pure Old Possum Piss]

System:
4" Stripping column, two 5500W elements.
Looked at the Calculators but couldn't find one that pertained to my problem.
Right now I use 11kw for heat up, about 20-30 mins on 25gals. Once producing, I must turn off an element, and then I can only go 60% power because I only have a 4" SS shot gun PC. I can add a 2"/1" liebig 24" long that allows me to run with one element at 100% and the other at about 10% or both about 60%.
I have found a good deal on 4"×12" shotguns and I am wondering how many feet of 4" SGs I would need to knock down about 17000W because i am going to add a third element. This is just for the Stripping side. I will eventually up grade the Spirit but can't afford it now.
It currently takes about 5 hours to strip 25 gals. It's over 100° in the shed during the day and in the 90s at night. I'd like to be able to do the strip in just a couple hours by by maximizing the system.
Thanks for listening.