I have an arrow arum that I'm moving to my larger pond. It's currently planted in a glazed terra cotta type pot. Is it okay to leave it in that or does it need to be in a basket type pot? Also, to have the top of the pot at the right depth, I'd need to set the pot on something. Is an upside down regular terra cotta pot ok for that? I've had string algae in the barrel ponds so I'm trying to scrub anything that will be moved to the new pond really well. Or am I wasting my time doing that?