Stretching Zoas/palys normal?

[sfsuphysics]

Just a question to all you Zoa/Paly experts. I've noticed recently that some of my zoas lower in the tank have REALLY long stalks, like 3-4 inches, and I'm wondering if they're stretching because they're not getting enough light/shaded too much. Others that are lower in the tank aren't doing anything however, so I don't know if it's specific to that color morph, or there's some other issues involved.

Anyways, is this a bad sign? Not enough light? (which is hard to believe for Zoas) lighting consists of 2-54w Geissman Actinic plus (blue) bulbs + 2-175w 12000k reeflux bulbs.

 

[Elite]

I don't know why they are like that but I don't think it's the light either. I had some like that about 25" under 400W MH Radium bulb.