I would like to set-up my planted tank with both a soil substrate and sand. When I see this being done, it looks like cardboard is placed between the two in the initial set-up then it is removed. It would seem that that would make for a real pain keeping them seperated. If not I would love to know how that works.

I was thinking of making up 3 inch wide longs strips of acrylic and using them a a permanent barrier between the two substrates. Would this work? Has anyone ever tried this?