I can control the chances of overwatering by taking them to the sink and letting the water all drain out. That’s the way they get watered in nature as they’re growing on other plants and rocks and those showers blow through. Second, these are tropical plants which like cozy conditions when it comes to temperature. I can’t image they like frozen water melting into them!
The den-phal type are warm growing year round and do, just by happenstance, bear flowers similar in appearance to the genus Phalaenopsis. They can be distinguished by plant habit (most Dendrobium have pseudobulbs that resemble tall canes) and flower shape. Den-phals have a spur at the back of the lip; some are more pronounced, others less. They are also borne on very strong upright to barely arching stems. Interesting to note, den-phals can rebloom on old canes.
The Cypripedioideae subfamily is known for its lady slipper orchids, which are named after their slipper-shaped pouches that trap insects and help the flowers get pollinated. There are 5 genera in this subfamily: Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium, and Selenipedium. Cypripedioideae orchids have two lateral, fertile anthers, which is unusual in most other orchids.
One of the most interesting things about growing any type of orchid is how they grow. Most of the houseplant orchids and even lady slipper orchids need good air flow around their roots. With indoor orchids, use an orchid potting mix that features some kind of blend of composted bark, expanded clay pellets, hardwood charcoal and peat moss or sand. The mix should create many air pockets for orchid roots to breathe.
Most orchids are not heavy feeders. Many orchids bloom year after year with no fertilizer at all. During active growth, when new leaves are being produced, you may fertilize every other time you water at half the strength recommended on the fertilizer package. However, it's important to deliver water without fertilizer at least once a month to flush excess fertilizer salts from the bark mix and avoid fertilizer burn to the roots.