Interesting idea!
I am working on a similardesign as well and I think your design looks like it will provide nice filtration
I do think that you should put 2-3 or so stacked boxes in the "filter area", pretty much like a canister filter. The lower box could have bioballs for easy waterflow, and the top box gravel to plant in. The sponge to the far right is great to catch particales trying to get into your pump. You would need some kind of grid in the bottom of the top box, but this way its easy to pick them up and clean if they clog.
If you manage to get a good enough flow your emersed plants are gonna have a blast!
I am working on a similardesign as well and I think your design looks like it will provide nice filtration
I do think that you should put 2-3 or so stacked boxes in the "filter area", pretty much like a canister filter. The lower box could have bioballs for easy waterflow, and the top box gravel to plant in. The sponge to the far right is great to catch particales trying to get into your pump. You would need some kind of grid in the bottom of the top box, but this way its easy to pick them up and clean if they clog.
If you manage to get a good enough flow your emersed plants are gonna have a blast!