Hoya Gracilis (also commonly known as Hoya Memoria) is a fairly new variety in the market, making it more uncommon than other Hoyas.
It can tolerate some morning or evening light but avoid hot midday sun or the leaves will yellow and scorch.
We recommend keeping your Hoya's on the drier side. Water thoroughly, allowing excess to drain only when soil is completely dry. A waterlogged soil will also lead to yellowing leaves. Never allow the plant's roots or leaves to sit in standing water.