Strange zoa observation

[Nanook]

I've had a couple colonies of zoas start as small frags and grow out nicely to about 50+ polyps. Then, I will notice a few zoas on the outside edges closing up and becoming loose and falling away. The other polyps will close and sometimes the whole colony will eventually die off and sometimes it won't. I do have the asterina stars, but I have limited their numbers substantially and I am not seeing them as the culprit here. Any thoughts?

 

[A. Grandis]

Oh... could be so hard to figure that out!

Check your alkalinity and Mg!!! Make sure pH is between 7.9 to 8.4.

Are they getting good water flow?

Make sure there is nothing irritating them, and no predators. Check at night!!

Assuming all the parameters around normal and acceptable ranges, no predators and no poisoning of any sort...

Do you target feed them?

I would say it could be a nutrient deficiency, and I would target feed them to check that out. If so, they will probably come back slowly. You can start offering them a quality coral food like: Reef Roids, Coral Frenzy or Fauna Marin zoa food.

Normally the polyps grow good, but after a while they get weak and loose their ability to close on food or touch. After that they begin to shrink and loose their colors a bit. They need food particles!!!

If you wouldn't target feed them, you won't know how good that would be to them.
Go slow and offer only what they can ingest. Once a week is enough.

That's my $.02.

Grandis.

 

[Nanook]

 

[Nanook]

 

[Nanook]

Oh... could be so hard to figure that out!

Check your alkalinity and Mg!!! Make sure pH is between 7.9 to 8.4.

Are they getting good water flow?

Make sure there is nothing irritating them, and no predators. Check at night!!

Assuming all the parameters around normal and acceptable ranges, no predators and no poisoning of any sort...

Do you target feed them?

I would say it could be a nutrient deficiency, and I would target feed them to check that out. If so, they will probably come back slowly. You can start offering them a quality coral food like: Reef Roids, Coral Frenzy or Fauna Marin zoa food.

Normally the polyps grow good, but after a while they get weak and loose their ability to close on food or touch. After that they begin to shrink and loose their colors a bit. They need food particles!!!

If you wouldn't target feed them, you won't know how good that would be to them.
Go slow and offer only what they can ingest. Once a week is enough.

That's my $.02.

Grandis.

I do not target feed them, perhaps I should try that. I do feed the fish and the zoas might be getting some food, but not much. I keep my alk 9-10 and ph is 8.2-8.4 consistently. I have good flow and they polyps are all under 250 watt Phoenix 14K bulbs and vho super actinics. I have looked at night and not seen any critters and I've dipped everything I've put in this tank. Maybe feeding will help and I will try it....any tips for feeding? Turn flow off?

 

[A. Grandis]

Yes, turn off the flow if you wish to target feed them.

Your colony looks very healthy. Thanks for the pictures!
I would imagine that there is something irritating them, perhaps.
Not a big deal.

Maybe they would love to have some more white from the light also. Just my opinion. Most of the zoas I find are in very shallow water, so I think most species have the tendency to like the wormer spectrum. I like to keep my zoas under 6500K and 10000K bulbs with the supplementary blue bulbs.
That's touching your tastes, because you probably like the blue look from the 14K and actinics. Many other people keep them like you do...
They do show stalks a little long.

When I had MH they were 6500K and the actinics.
The zoas' growth is amazing under those!!!

Give them some food and check closely for irritation. Herbivore amphipods, hermit crabs, vermetid snails, fishes etc...

Good luck!!

Grandis.

 

[Nanook]

I do have vermetid snails in the tank and need to trim a few of them back, but they are not in the areas where the zoas are dying off. I will try target feeding them a bit with the pumps off and see how they do. I have a lot of flow in these tanks and the Phoenix 14K 250s give a fair amount of light and I like their color. I have used 10K 400 watt Ushio's in the past and they are just too bright and a bit too yellow for my tastes. The bluer Phoenix are more mellow for my displays.

I don't have any crabs in the tank and my wrasses keep the amphipods at bay. I do have a couple Klein's Butterflyfish, but I never see them nipping at polyps (at least in the daytime). Thanks for the help and compliments

 

[A. Grandis]

Yeah, no problem.
Some species of vermetids can be a pain!!!
I know... if you like the blue lights, that's it.
Are you sure the flame angel is not nipping at it a bit?
All the angels I've tried here did nip on my zoas in the past.
I hope your zoas can get better soon.
Let us know about the feeding...
:thumbsup:

Grandis.

 

[RandysReef]

I think they are melting, but i dont know

 

[Nanook]

OK, I found the culprits! I have two Klein's Butterflyfish that have been in the tank for a year or two that took a liking to the zoanthids at night time. I caught them the other night eating them and they are openly picking at them in the daylight now. I am going to borrow a trap and get rid of them....good aiptasia eaters, but now they are eating more expensive treats:hammer:

 

[A. Grandis]

I thought was the angel.
Good that you caught them!!!
:lol2:

Grandis.