do not be impatient, he is Vietnamese, the language barrier makes him hard to guide you in detail. as far as I know he was looking for the lost photos, pictures were taken when he made these islands, then he will share for you
I'm the one who was impatient, not crazydaz.
If I was too impatient and vhnam0084 is still working on getting the rest of the information up, then I apologize.
Hey, leave vhnam alone to keep his tricks! Why not figure it out on your own?
I did. Sort of.
Obviously I went for a different look, as seen in my photo. That part I'm happy with, the rest not so much; and while I'm too embarrassed to share a final, in in-tank photo, I'll share what I did.
The island was sculpted from green floral foam. Behind some of the stalactites/fingers/whatnot, there are hidden holes where some hanging roots can be pulled through; as in addition to moss I'm going for some "trees" too. Not shown in the photo is a separate topside hill, which was attached later and covered in clado.
I took some fines from a bag of hardwood lump charcoal, pulverized them in a blender, and double sifted through a fine mesh until only powder remained.
Working in small batches and sections, I mixed common two-part epoxy with a tiny bit of the charcoal powder, applied to the foam with disposable brushes, then pressed Flourite Dark into the epoxy. This gave a "stones embedded in soil" appearance. A bit of the foam's green shows through gaps in the substrate, with the amount depending on epoxy thickness, which adds a more variegated appearance.
For mounting, I used two suction cups with hooks. The hooks were straightened out with pliers into spikes, at a downward angle. I figured as the island would be trying to lift up due to its buoyancy, this angle would keep the island from slipping off.
Added mosses, clado, "trees". Shoved the island into the spikes. And wow, did I ever underestimate the buoyancy of the island. The spikes tore mostly through the foam, leaving the island barely hanging on at an extreme upward angle. I had to use a fishing hook attached to the front of the island, with fishing line run to a big rock in the substrate, to stabilize it. The only rock I had heavy enough doesn't match the decor at all.
After the island grows out enough that I can learn what other mistakes I made, I'll do a second version. This time I will probably use stronger, closed-cell foam. Bismuth or epoxy-encapsulated lead weights embedded in the foam to approximately cancel the buoyancy. And instead of suction cups, magnets covered in Plasti Dip to prevent corrosion and give a non-slip, non-scratching surface. I may or may not try a different epoxy. The common stuff, being thick and viscous, made it super easy to attach the Flourite; but was hard to brush on and cured way too fast.