The only differences between the Pro3 & 4 are in the overall size and the components within the unit. The design layout is exactly the same for both models.
SolarPro300 (Pro3) pulls 300 watts, is 32" x 8" x 3.15" in dimension and utilizes the top-bin CREE CXB-3070 COB's with supplemental XP-G2 and XP-E2 5w monochrome diodes. The coverage of the SolarPro300 is as follows:
1 panel: 2' x 4'
2x: 4' x 4'
3x: 5' x 5'
SolarPro400 (Pro4) pulls 400 watts, is 36" x 9" x 4" in dimension and utilizes the top-bin CREE CXB-3590 COB's with supplemental XP-G2 and XP-E2 5w monochrome diodes. The coverage of the SolarPro400 is as follows:
1 panel: 2.5' x 4.5'
2x: 5' x 5'
Why not use the 3590 on the pro3?