This is so nice!
So where the black sponge go? On top of the mesh? Basically what is the riccia sitting on?
The black sponges goes in the HOB on top of the stock filter material, like a lid. Doesn't go down into the tank at all.
The ricca is sitting in the bowl of the SS Mesh 'spoon', and having the bowl shape has kept it matted together better than having a flat ramp (so far)
This might give a better idea of what I am thinking when I say a 'spoon shape', imagine the ricca sitting in the spoon.
But the bowl is shaped more like a rice spoon