If it is packed in too heavily then it will not get enough light to to lower layers. Like shown in the DIY link aquarist48 posted, the moss is layered pretty thin. Basically there is little overlap while filling in the spaces as best as possible. Here's the one that I put together showing the growth almost two weeks after making it https://www.fishlore.com/aquariumfishforum/threads/my-diy-java-moss-wall.127010/. There is more now, so I should probably update it with some new pictures.BigOlePappy said:Will the moss packed in deep that doesn't get light eventually brown and rot? Especially if it starts growing out?
From the right angle you can see the coloring of the moss in the mesh to see if it turns brown. As for how long, it will depend on you lighting and the available fertilizers. Under low light with no fertilization java moss grows pretty slow. On mine, it is under moderate to high light from a dual T5HO fixture (currently only one bulb to battle algae) and it gets liquid fertilizers, so the growth is a bit faster.BigOlePappy said:How long without it growing through the mesh should I be concerned? I want to check it at some point to make sure it isn't rotting.