Another substrate idea
I want to put a cap of very fine sand on top of a clay substrate such as ADA.
To prevent the sand eventually sinking I was thinking of placing a layer of shade cloth (or similar) between the two layers.
The idea is ;
1. Sinking of the sand will be prevented (or at least slowed)
2. Plant roots can find their way through to the ADA
3. To prevent potential sulphide build up in what would be a thicker layer of sand.
PS. At what depth of sand does hydrogen sulphide start to build up ?