The use of using Hylocereus as the recipient plant is wrong. This is a tropical cactus which requires more water than regular cactus. Also mixing with other plants with different requirements is leading to trouble. Using almost any column types would be more of a close match. I don't know why they don't use other stock when I see them for sale. I guess Hylocereus is cheap and easy to grow. I have lots of it growing after the top rots off. I cut and throw away excess growth.