Thanks,
Many of the aquatic plants, most in fact, have very different emergent forms , most of which few aquarist have ever seen, including downoi in general.
I might go with slaked slate skree with caves for the Tropheus moorii display. Onyx sand is similar in coloration. But, a lighter colored rock might high light the coloration of the fish.
Darker colors sometimes look bad on some fish species. We have plenty of different flat stone to chose from. I can delete a few spots to make caves for fish etc.
I do not want to use foam or artificial materials.
Against my rules
I've looked at it, seen it, and done it to a high level. But I do not like it in my own tanks.
Drilled stainless steel rod with pre drilled rock(using ceramic drill bits) is another idea for taller columns(Rock forest of stacked slate, flagstones etc).
This is sort of like China's rock forest or the Capital Reef, Monument Valley, Zion, Bryce canyon type of landscape.
These can be adjusted around the center hole to give various looks without permanent gluing etc. Sort of like stacks of cogs on a bike's rear cog set but in a vertical position.
I've seen some really nice rock displays in nature, but getting them out and back home.........it would require a fork life to places that I could not get a fork life to.
Not sure yet.
The 120 will be a bit easier since it's with wood that I have plenty of already and know how to get it like I want.
One of the nicest tanks I've seen ever was a Tropheus rock Anubias display.
Regards,
Tom Barr