I have never been able to get any plant grown using leca and passive hydro to last much longer than one year before succumbing to root rot. It requires constant flushing of the media to keep ahead of it, which is way too much work especially when you have most of your plants growing in tents, which make the plants hard to access. I have seen some gorgeous Hoyas grown in leca on Instagram, but I cannot seem to achieve the same results, and it is maddening. So while it worked out in the case of this undulata, I can hardly recommend it as a main course of growing.