Cattleya species, I just started establishing my collection about a year and one-half ago so many are not flowering size yet. By the end of this year I expect to have plants of most every Cattleya species. It seems a well established fact that a number of Cattleya are influenced by daylength, there are a number of references. Here is from an AOS "Orchids" magazine article (Lopez and Runkle, Orchids, March 2004, page 200):
http://sharepoint.agriculture.purdue...%20orchids.pdf
Cattleya is a genus composed of 60 species native to tropical regions of Central and South America. This epiphytic plant is generally found growing on trees of moist and wet forests from sea level to 4,900 feet (1,500 m) in elevation. Several published scientific studies indicate that flowering of Cattleya species and hybrids is promoted by exposure to short daylengths and cool temperatures. For example, in Cattleya warscewiczii, Cattleya gaskelliana and Cattleya mossiae, flower induction occurred only when plants were placed under photoperiods of nine hours (nine hours of light per day) at 55 F (13 C), while flowering was inhibited under 16hours of light (per day) at 55 F (Rotor, 1952, 1959). These represent but a small sample from this genus, which also contains long-day species, as well as both short-day spring- and autumn flowering types.

Another article by Lopez and Runkle:
https://sharepoint.agriculture.purdu...0-%20color.pdf

Ohhh.
I am impressed that you will have accuired most of the Cattleya´s within 2 years! I would like to grow more Cattleya´s but have not the space :-(

And I agree that they can be dependent on the length of the day. It will be interesting to follow your ecperiments, especially if you have the ability to compare the far red light treatment you plan with normal darkness.