Blc. is the variety your Liu's Joyance 'Water No. 8' is. The water in the name doesn't have anything to do with watering the plant. Trust me, there is little rhyme or reason to orchid names, except possibly to the person who named them. There are something like 30,000 different varieties of orchid and you bought 4 different ones. Oncidium, Dendrobium, Zygopetalum and the Blc which stands for Brassolaeliocattleya (which btw is an out of date name, don't ask!)
Those orchids you bought all need to be potted in a bark mixture. You can buy it in bags at Home Depot or Lowe's. Stick your finger down into the pots and if what you feel is soggy mossy stuff, it's probably a really good idea to re-pot them all. The bag of bark mix has good instructions on how to do this. While you're shopping, better buy yourself a sprayer bottle for spraying your new plants with water (to keep the humidity high around them) and a little packet of orchid fertilizer.
Here's a link to the American Orchid Society's culture sheets for orchids.
http://www.aos.org/Default.asp... They obviously can't do a sheet for all umpteen thousand varieties so, for example your Blc you'd use the Cattleya culture sheet.. I think your Zygo is related to Oncidiums most closely, but I may be wrong about that.
