To be honest with you, I didn’t really like Avatar. The plot was fairly predictable without being moving, and it didn’t surprise or captivate me. I have to admit, though: the one thing that Avatar did exceptionally was the graphics. The Avatar world looked absolutely awesome. Probably the most memorable set piece was the area with floating islands, which they explained away with magnetism or something to that effect. It’s normally impossible to replicate those gravity-defying scenes from Avatar, but aquascapers have come up with clever alternatives.
The technique is brilliantly simple. Basically, the aquascaper begins by attaching a wire mesh or some other lightweight material to the side of a tank. The aquascaper then fills the wire mesh with substrate before planting moss or other carpet plants onto the islands. Eventually, the plants cover up the island completely and you end up with a lush green Avatar-style island that seems to hover above your aquascape.
The aquascape in the video below uses a different strategy. It might look like the islands are simply floating in midair (or midwater), but they’re actually connected to the aquarium with hard-to-see support beams.
(By the way, if you’re also wondering how that aquarium pulled off the underwater waterfall, you can read all about it here.)
Unfortunately, it would be practically impossible to create a naturally buoyant formation. An object’s buoyancy determines whether it floats or sinks, and if an object has perfectly neutral buoyancy then it can hover in place. The main problem with an island like this is that plants aren’t perfectly buoyant, so the island’s buoyancy would gradually change as plant life grows across its surface. Pretty much the only long-term solution is to anchor the floating island to another part of the aquascape.
Fortunately, there are a couple of different ways to do this. One solution would be to “hang” the aquarium from a support beam that sticks out of the back of your aquarium, much like hanging a portrait on a nail. The support beam would be difficult to see because it’s behind the island, so it will give it the illusion of floating. You could suspend a relatively large island on a small support because objects weigh so much less in water.
Another solution would be to create a heavier-than-water island and suspend it from a thin wire. The advantage of this technique is that the island would sway slightly under the current, thereby adding to the feeling of a free-floating island.
There’s a third solution that’s a lot of people probably wouldn’t think of. You can always create a lighter-than-water island by filling it with air, kind of like a balloon, and then anchor it to the ground of your aquarium with a thin wire. The island would float in the middle of the aquascape and sway much like the suspended aquarium, but the advantage is that it would be much easier to hide the wire. Since most aquariums have a top-down light source, the wire would be hidden beneath the shadow of the island. Plants would also grow upward and obscure the wire. Add that to the fact that most people wouldn’t think to look for a wire anchor beneath the island, and you’ve got a magical aquascape that’s sure to bewilder your friends and family.