Around the two year mark, one of my potted specimens developed root rot and needed to be started over. I took several cuttings and potted them up in a mixture of coconut husk chips and oyster shell. All that I knew about Eriostemma Section Hoyas was a remembrance of what Carol Noel posted several times in the Hoya forums of the day. She said that they needed full sun, lots of calcium in their soil mix, warm temperatures, and had to get big enough to hang down in order to flower. The one thing that I could most easily provide was the calcium from shells in their mix so that is why I used this mix.