I wish I could give you care instructions for Hoya filiformis, but unfortunately I have made out very badly with the plant.  Right after the plant bloomed it went downhill so badly that I threw the plant into the trash can.  After 24 hours, I dug it out and restarted it in Growstones using the semi-hydro method.  I grew my plant in soil and had a very difficult time getting the conditions right for this plant.