Zoanthids are shriveling

[uh duh]

I'm having problems with several colonies of zoanthids that I cannot figure out. First off, my water parameters are all normal except nitrates might be a tad high at 40ppm. Lighting is 260w PC on about 8 hours, and 250 watt MH on about 2 hours a day on my 55 gal. Fish, inverts and other corals are fine.

well, I have about 6-7 colonies or various zoanthids all on about 3-4 inch rocks. And I noticed couple colonies started shriveling over a period of couple weeks while still open. It starts with the base disappearing(the part that spreads across the rock), then the polyps disappearing. They still all open up but then the heads start disappearing.

I cannot figure it out, I tried moving them to different locations and they're still the same. I tried looking for nudibranches at night but didn't see any. I did an iodine dip but they're still disappearing.

My only guesses are maybe that nitrates are too high, too little water flow or too much lighting. Can too much lighting make the zoanthids die? or Are zoanthids supposed to be in direct flow of the pump for higher water movement? Or can I do a big water change like 60% to lower nitrates? I'd really appreciate any help! thanks

 

[melosu58]

Instead of one 60% PWC I would do 2 30% PWC`s. Smaller more frequent is better IMO. And yes your nitrates could be a problem.

 

[afishyonados]

Try lowering them a little as well.

 

[MT79]

My only guesses are maybe that nitrates are too high

Definitely. Nitrates should be less than 20ppm, ideally zero when keeping inverts. A few large PWC's should bring them down assuming the water source is free of nitrates.

too little water flow

Possible but unlikely if water params are good.

Can too much lighting make the zoanthids die?

Yes. Although they are very tolerant of many different types of lighting, a drastic shift either way can cause them stress. Where they a recent addition? If so what type of lighting were they being kept under? The MH may be stressing them if they are acclimated to fluorescent lamps.

 

[phish7740]

you could also try an iodine dip, i did that when mine closed for a week and now they are multiplying like crazy.