Zoas "thinning" skirts....why?

RandoReefer · Jan 4, 2015

Alright Zoa fanatics. I keep all my zoas in my frag tank, as they do not do very well in my SPS display.

Recently, their skirts have been thinning out. Unlike those fat and happy skirts I see on other people's zoas, mine started that way and are now getting thin.

I recently added a Refugium to the frag tank and since my nutrient levels have gone down significantly.

Nitrate: ~0.0ppm (Salifert)
Phosphates: 0.03ppm (Hanna)

LED light fixture: Ebay full spectrum. ~50% intensity for 5-6hrs all lights on.

To me, it feels like I need more nutrients in the tank, but I'm an SPS head and haven't had much luck with Zoas.

Thoughts??

Oscaror · Jan 4, 2015

that's really weird. Bump!

RandoReefer · Jan 4, 2015

Oscaror said:
that's really weird. Bump!

Thanks Oscaror I'll try to get pics tomorrow.

I've bumped up feeding for my purple tang in there. He's happy, hopefully the zoas will be too.

lionfish5740 · Jan 5, 2015

That is odd. I've heard people say that flow can contribute to the size of the skirts, not sure how true that is. I seem to buy them and their skirts get bigger.

I would wonder if it has something to do with you having zero NO3. I find that my corals are happier when I have detectable levels of NO3 and PO4.
Just my 2 cents

RandoReefer · Jan 6, 2015

lionfish5740 said:
That is odd. I've heard people say that flow can contribute to the size of the skirts, not sure how true that is. I seem to buy them and their skirts get bigger.

I would wonder if it has something to do with you having zero NO3. I find that my corals are happier when I have detectable levels of NO3 and PO4.
Just my 2 cents

I did lower my MP10s to a softer Lagoon setting and have been feeding a bit more heavy. We'll see if this starts to fatten them up. Thanks!

glweek · Jun 7, 2015

im interested how this works out, i have thinning skirts as well.

OrlandoReefer · Jun 7, 2015

Some zoas will extend their skirts during high flow and in low flow situations they will retract their skirts but not to extreme levels that look unhealthy, most zoas enjoy moderate flow but I've grown plenty of zoas in areas with very low flow. However another problem you could be having is something in your tank that is eating the skirts, there are many critters that will destroy the skirts of zoas. A friend of mine had a zoa eating nudibranch that would eat the skirts of his zoas until then eventually the coral disappeared entirely. My advice wait till late at night and get a light and check out the corals to see if you see any critters are walking around your zoas, also familiarize yourself with zoa eating critters and how to get rid of them. Another issue could be that your water is just too clean zoas thrive in tanks with small amounts of nitrates they could be adjusting to your new setup and maybe they'll bounce back. Add some photos of the zoas and we could see if there is actual damage to the zoa from a critter or if they are just unhappy. If they are unhappy due to the change you made Id just wait it out and watch them for awhile they'll more than likely bounce back. Your lighting should be just fine for the zoas and Ive heard sps dominant tanks are just to pure for zoas to thrive in. Hope this helps.

DLdraconias · Jun 7, 2015

Following, I've lost zoos lately to this

Oscaror · Jun 7, 2015

You know what zoas love, fish poop. You don't have enough of it. This might not be the only cause but this is definitely a factor

saltyphish · Jun 7, 2015

I think oscarer has it right. My zoas didn't start looking healthier until I allowed some nutrients to build up.

Legendary Corals · Jun 8, 2015

Oscaror said:
You know what zoas love, fish poop. You don't have enough of it. This might not be the only cause but this is definitely a factor

+1 on this. Fish poop really makes our zoas plump up. I also noticed that you're running your LEDs at 50%. Is it only controllable with the intensity? If you can make it mostly blue with very little whites, it should also help. We run our zoanthid propogation system that way and see great results.

WetWhistle · Jun 8, 2015

One of the factors causing this is your water is to clean judging by the zeros I see, they typically like a little dirtier water then what you have. One of the primary ways of feeding for zoas is uptake of dissolved organics to be used as a fuel source so if NO3 and PO4 levels are to low they loose one of the primary modes of feedin. You can try and increase spot feeding the zoas to make up for this. I like to blow off the rocks and stir up detritus for them as this is an excellent energy packed food source.

Zoas do autotrophic and heterotrophic feeding for their energy needs. They gain a large portion of their daily needs through uptake of nutrients and dissolved organics across the cell wall. (Skin) Active feeding and the byproducts of Zooxanthellae algae are some of the other ways that make up feeding. If the coral is not getting enough nutrition it will reduce the amount of body mass that is has by eating some of itself. So it can reduce the amount needed for its energy budget needs. Less mass = less energy.

Eric Borneman has a good book with a great chapter on coral feeding and nutrition in his book 'Aquarium Corals : Selection, Husbandry, and Natural History'. It is quite informative on coral needs.

You should look for predators as well as a precaution.