This premium soil mix by Sybotanica has everything your hoya plants need. This soil mix is peat free, and contains perlite, worm castings to improve growth and aid drainage. Comes in a re-sealable bag. 

The added activated carbon helps prevent root-rot-related issues. There is orchid bark & coco husk to support space and aeration for the larger roots. The mix drains relatively quickly as Hoyas prefer to be left to dry between watering. 

Hoya’s thrive on bright, indirect sunlight and can be left to dry for quite a bit. Similar to succulents, you can check to see if a hoya is thirsty by feeling the leaves. If they are not as plump as before they are probably thirsty and can use a drink.