I may not be the best person to give growing instructions for Hoya sp. IV From WMZ because of my struggles with it over the years. Here are my experiences:
1. Must be grown in high humidity – simply won’t grow without it.
2. Likes it warm – doesn’t seem to want to grow below 70°F (21°C)
3. Don’t over pot – surest way to shut it down for a long time.
4. Keep on the dry side – roots very susceptible to over watering damage.
5. Prefers sunshine to artificial lighting – Always grew best out of doors in the summer.