My Cattleya's won't bloom

[Ray]

There are several factors that might quash blooming in catts.

One would be excessive nitrogen. "1/2 strength, weekly" is of no value assessing that. What is the formula and how much per gallon are you using?

Another is species in the background, and estacion seca's request for the specific plants nailed that. Some species are "short day" bloomers, meaning they will not initiate blooming until the lighting is shortened drastically for a few weeks. Not all are like that, but it does provide a way to analyze the situation better.