I don't think fluorescent can ever be bright enough , but perhaps used as a supplement to natural light might help - but I have successfully grown what we used to call odontoglossum hybrids ( O.crispum hybrids) under fluorescents, after deflasking and had them 6 inches away from the tube - that was long before the idea of using a light meter ever occurred to me, and I could now only speculate how much light it gave - I would guess it was only a few thousand lux = a few hundred Fc.