Awesome tank man. Couple of questions for you.
1. How do you deal w/ the heat form the PCs
2. Why keep the 3 compartment in back empty?
It's made to stack three sponges in C1 for wet to dry, this increases oxygenation and stabilizes pH as well as provides a good area for N & D-N bacteria to colonize. Second up-flow C is for whatever pleases you from Ceramic disc to carbon to any bagged media for good water contact surface area. C3 is for return pump and a heater will fit nicely in compartment as well.
Here's a pic of my All Zoa Garden in my stock JBJ 12G DX LED w/ ceramic disc, carbon, Purigen and Phosguard running in the 2C. This tank has been up and running for 6 months and is one of 7 JBJ BC tanks I currently have running between home and office.
Bio-Load = 1 mating pair of Pink Skunk Clowns (Feed Heavy), 1 Skunk Cleaner Shrimp, and 12 Red -Legged Crabs. (Crabs removed when they lay eggs)
Params = 78.5 F, 1.025 SG, Amm and Nitrites = 0.0, Nitrates ~5 ppm, PO4 < 0.04