Hello Hoyahead, Lin has given you a good suggestion...increase airflow around your plants, especially with your Hoyas. As for the Kalanchoe tomentosa, I have always found this plant much better to grow outdoors, it can take a bit more direct sun since it has fuzzy leaves, but in the afternoons best to have it in some dappled sun area. Depending on your summer situation, if it is rainy, got to allow good dry out time, to avoid those fungal looking scars. If it is too dry and no rain like my area, then water generously, but still allow excess water to drain out properly.
