View Full Version : Is this bad? Zoanthids shrinking

11/05/2009, 08:11 PM
I bought these zoanthids and a few palys from my LFS about 8 months ago. They did really well under my old 65w PC in a 55G. Here's what they looked like under the old light...


Since then I added a 4 bulb t5 tek light from Reef Geek. My zoanthids shrunk back, and now they look like this...


And they are shrinking a little more every day. Are they dieing slowly, or is that the way they deal with excess light?


11/05/2009, 08:16 PM
could be light shock...but 1st what is all your water parameters ?

11/05/2009, 08:30 PM

Lights stay on for 8 hours, and they are on the bottom of the rock scape. (get the least light)

11/05/2009, 08:51 PM
I would say based on the pictures its the lighting. In the first pic, look how much longer the stalks are - they're trying to reach up to the light. To me in the second picture they look much healthier (not reaching) and once acclimated to the new light will probably look beautiful. To avoid shock, you might want to cut down your light schedule a bit or put some layers of window screen over the tank and remove one at a time over the next few weeks to avoid the shock of the new light.

11/06/2009, 06:28 AM
I thought they would acclimate to the light too, but its been 2 months and they're even smaller than in the 2nd picture. I tried moving them to a darker spot yesterday so I'll see if they come out more today. Should I try acclimating again even slower or do you think they will adjust by themselves?

11/06/2009, 06:40 AM
I think if it has been two months there isn't much else you can do unless you keep them in a shaded area and slowly moce them closer to where you want them. This is, of course, assuming that the issue is with light.

11/06/2009, 06:58 AM
I would agree with Ritten. It looks like they are reacting to the stronger light. When I raised my lights as an experiment most of my zoos stretched up as if reaching for the light. When I lowered the light again they settled back down.

11/06/2009, 09:23 AM
If they are just shrinking down, and not melting/losing polyps, it looks like the light issue the above posters mentioned. If the polyps are disappearing and the colony is shrinking, that is some other issue.