Still can't figure out my mottled leaved Phals?

[Phal grower]

Hi friends! I am growing about a dozen Phals under lights (two forty watt bulbs) with natural light as well. I have green leaved and mottled leaved plants. My mystery is this. My green leaved plants are doing great, big leaves as well. All my Phals are planted in the same mix and have good roots (I plant in clear plastic so i can see whats going on). So my question is why are the mottleds giving me smaller leaves? Do they need more or less light than the greens? They have the same culture, they are mini's I think, but so are some of my green ones. I moved them closer to the lights and they're leaves got even smaller. Now I'm at a loss. I really like those little mottleds and I needs some help. Do I move them further from the light and will smaller leaves effect blooming? I always thought big leaves means a healthy plant and big blooms. Hmmm? Thanks for any comments