Xenia thrives in less than perfect water quality. If your water quality is top notch Xenia won't surivive, so that should answer both questions here.
Xenia is either going to grow like mad or die off, there's very little middle ground. If you want to get rid of it, then work to reduce your phosphate levels first and foremost. However if it is doing well in your system, you can make good money selling frags to LFSs.