Hi Corey87,

Most "moon cacti" (grafted cacti with bright, colourful tops) have hylocereus undatus (dragon fruit cactus) as their base/stalk. You could purchase one of these, and lop off the gymnocalcium (top) with a sterile tool.

Ok I have a couple of those, I never knew that before, does the "moon" prevent the still from flowering as a typical dragon fruit cactus? Once I cut off the moon should I replant? Change soil? Direct sun? Shade? Water?

Could you post a picture of the "moon cactus" that you have? Sometimes they're grafted onto something other than a hylocereus undatus. As for the top (gymnocalycium), if it's brightly coloured then their isn't any point in trying to replant - it can't produce chlorophyll, so it will die. If it's darkly coloured or has some green to it, then you could try to root it by nestling it into some perlite or your choice of rooting medium, keeping it in a bright location with indirect sun, then lightly misting (NOT watering) the rooting medium PRN until roots are present.

As for the hylocereus - it should be quite happy after being freed from the burden of the gymno. You can sprinkle the cut area with cinnamon as an antibacterial measure.

If you're growing indoors, direct light is best. Water when the soil is quite dry. It's pretty good at letting you know when it needs water; it will start to feel a bit softer and get slightly wrinked when it needs a drink. What sort of soil do you have it in currently?

I cut off the moon and sprinkled some cinnamon over the newly "flesh" of the stock. It's in the original pot from when I bought it. I believe the soil is c and s mixed with a small amount or perlite

Great! It definitely looks like a hylocereus undatus. The soil that it's in looks quite heavy/wet, so you should try to repot it after it heals. Do your best to get all of the old soil off of the roots, gently - some will inevitably break. Give it a couple of days to heal, outside of the potting medium, if some roots are broken.

You have some options for potting mediums; you could do a basic 50/50 perlite and C&S mix, or you could go all out and mix up a gritty mix (search this forum for "Al's gritty mix"), which would be a good choice especially if you have other cacti and succulents.