Lighting Sarcophytons

[tigé21v]

I have a couple of sarcos I'm going to be moving to another tank.
They're each growing directly under 250 watt metal halides. They've reached the point that they're about 12-14" from the lamps.
I want to drop them all they way to the sand in the new tank. The new tank is 27"deep, and I'm probably going to mount the MH's 18-24" above the water surface.
Am I going to have to step up to 400 watt bulbs, or can I get away with just increasing the photo period? I'd like to see them keep growing like they've been.
TIA

 

[P-Dub]

That's a tough call. If it were me, I would put them in the new tank with your 250's and watch and see. If they are showing a persistent and significant adverse response, then switch to 400's. They are looking good now.