How?

[Jayva]

Reef puffy? Silicone? I have the perfect 1lb rock with a shelf for this.

 

Give me some ideas how to stick rock to glass please!

 

[cruiZe]

It's probably rock that's been cemented together and to a hanging rod, hung on the glass . I've seen them on eBay and other places on nano reef . It looks like the Rock is glued to the glass, but I doubt that's actually the case .

[SunWyrm]

Pond foam would work great if you can keep it from forming large blobs (or cover it with sand before it's dry to hide it). The above would probably require something to hold it overnight while it cures, like pvc or block of wood to keep it steady.

Requires a little brute force to come off a tank wall/floor but it comes off cleanly (and won't just fall off on it's own!).

I've used Touch n' Foam (beware of other brands, especially tuffstuff and those that aren't specifically made for ponds). Coralline covers it quickly and it's invert safe, although I wouldn't trust it with an urchin; nothing picked at it or ingested it with ill effects.

[gena]

They sell mag rocks. Maybe someone bought one of those and modified it with rods and cement.

[StevieT]

The Alternative Reef magnets

[cruiZe]

The Alternative Reef magnets

 

under the sand, causing the rocks to levitate?

[StevieT]

Or that

[Clown79]

I wouldn't glue a rock to glass.

 

This is most likely mag rocks or rods used.