I really like the look of a cacti and succulent terrarium, but I don't know how to make it last. Right now I have elephant bush, curiosity plant and old man of the andes and I put about an inch or two of gravel and rocks at the bottom to help with drainage, and then I poked holes in a plastic lid and placed it on top of the rocks and then put Miracle-Gro for Cacti, Palms and Citrus as the soil. Is this ok? How long do you think these plants could last like that? I want to put them in regular pots but I haven't found any that I like as much as the glass conatiner I have them in now. Thank you in advance!