Is my substrate layout viable?

[schleppey]

Setting up a few more caridina tanks here and am wanting to have the buffering substrate in a modular situation to avoid breaking down the tank. I am thinking of making a box out of plastic canvas, putting as much substrate as I would use normally into the box, and placing inert substrate around the rest of the tank. I have seen tons of tanks with substrate in glassed off sections and even in bins so I do not see why this would not work. I was also wondering how much active substrate is required to do its job correctly. In the past I have used it as standard substrate but with this I guess I can measure it more accurately.  Let me know if you see anything wrong or have some tips on this kind of setup. I made a diagram to show you my idea

[wyzazz]

Should work just fine, it looks similar to what Chris Roma (Roma Aquatics on Youtube) does with his "Soil Towers".  And I know Flip Aquatics just keeps disposable tupperware tubs filled with substrate in most of their Caridina tanks.  

[schleppey]

8 hours ago, wyzazz said:

Should work just fine, it looks similar to what Chris Roma (Roma Aquatics on Youtube) does with his "Soil Towers".  And I know Flip Aquatics just keeps disposable tupperware tubs filled with substrate in most of their Caridina tanks.  

 I recently saw Roma's setup and that was the final nail in the coffin that led me down this path. I was initially worried the substrate might not have enough flow through it or something, but Lups bin method disproves that theory. I am going to go for it I will post some follow up pics down the line.