| How long have they been in the loft space with plenty of morning sun and humidity? more than a full growing and flowering cycle?
The morning sun and good humidity are enough ot get cattleyas to bloom. What about your temps and watering? Are they good too? In the recommended ranges?
I'd leave them in the sunny loft for at least 6-12 months (at least one full growing/flowering cycle) before changing anything because it will take at least that long to be able to tell if it's right/enough for them.
Many people will probably tell you to buy lights. If your catts are getting plenty of morning sun, lights will not be necessary.
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