Elena, be careful with fertilizers and Paphs. Some enjoy occassional fertilizer, but some are extremely sensitive to salts and you can easily burn the leaves severely. Get to know the different sections of Paphs - they tend to have similar cultural requirements.
The larger, strap-leafed Paphs enjoy more light. Except for sanderianum, which actually thrives in much lower light than most Paphs. Parvis are extremely fertilizer intolerant. Definitely talk to the vendors you buy from and find out how they care for the plants.
Many Paphs like the calcium, because they grow on lime cliffs in their native environment. The easiest way to add it to you plants is to grind up egg shells and sprinkle that on top of the pot.