How does lighting affect the zoanthids?

[monpeasch]

Hi,
I've had my tank and zoos for just over a year and in the last weeks, the zoos are looking a little peaked. I've got green ones and red/orange ones. Both colonies are towards the bottom of the tank where they've been for several months (did a rearrange of the tank a while back) and were doing great until now. It looks like some of the green polyps are just disappearing and the surviving ones seem smaller than they were before and they're not as bright. My red ones are just smaller and the color is faded. but then, in the lower left corner of the tank, on the side of a rock, there's a colony that propogated itself that's doing great. Nice big, fat green polyps. My lights (metal halide + dual actincs, Outer Orbit HQI fixture) are about 1.5 years old, haven't changed the bulbs yet. What, specifically do the zoanthids need, the halide or the actinc lighting or both? I am currently trying to hunt down replacement bulbs but can't seem to find a website that sells them

Thanks!

 

[Strega]

The bulbs may be losing some of their intesity. You can't see this with your eye but over time bulbs become dimmer and may shift their frequency toward th red spectrum. I try to replace halides once a year and flouresence every six months.

 

[Siffy]

http://www.hellolights.com/ has their Ushio bulbs on sale and I think free shipping right now.

It's probably time to replace both MH and VHO bulbs.

 

[patej]

i think changing them out also will help