[Beedans]

I picked some up at Menagerie, and it's just plain melted into oblivion. It wasn't in the best shape when I bought it, but I thought my awesome light and good nutrients would help it out.

 

[TorontoPlantMan]

CO2 in my opinion is a must with this plant, at least from my experience.

 

[default]

I picked some up at Menagerie, and it's just plain melted into oblivion. It wasn't in the best shape when I bought it, but I thought my awesome light and good nutrients would help it out.

What substrate are you using? I've had the best results when in soft acidic substrate.
Also, did the stems themselves melt away or just the leaves? I've grown these in high light-low light, with and without co2, so just give it some time.

 

[Beedans]

I have fluorite sand in one tank and fluorite gravel in the other, and the plant has just vanished into oblivion. High light in the sand tank.

Hmm, maybe I need to get my co2 setup (I'm terrified, but I have all of the materials...).

 

[default]

I find the onyx to be a substrate with mixed results, I personally don't like it of much, but it works well for certain plants.
However what are your specs regarding lighting? Despite having grown them in low light, perhaps a lack of co2 and lighting caused the melt back.
I personally got some from a member and when I brought it home it was covered in hair algae and BBA, so managed to save 2-3 2" stems and placed them in a dip solution and it was near death at that point - but I placed it in a tank with aqua soil, high light, med co2, and high ferts - within a week it grew an inch or two.
Don't be intimidated by pressurized co2, I just think of it as having a large fire extinguisher around probably one of the safest pressurized gases around. Those oxygen tanks are frightful compared to co2!
If you still have the stems for the macranda and they aren't melted to nothing themselves, keep them and they might bounce back, get your co2 up!