Need Zoanthid advice before they die

[kurtwalk]

I am an advanced novice as a saltwater hobbyist.

I am trying to establish some of the easier corals but my zoanthid's are having problems. All parameters are constant - nitrates at 0, phosphates at .5, ammonia 0, PH is 8, temp 80.

I have tried upper mid and lower lighting (coralreef LEDs). I have tried medium and low flow areas, nothing seems to be working so I must have another problem.

In the picture I attached, I have some doing quite well and others are dying out.

Can one of you experts give me some pointers to revive my zoanthids?

 

[A. Grandis]

I am NO expert in anything related to reef keeping, but I know the best way to start this thread would be giving more info about your system, so people could try to help you.

We are a bunch of hobbyists here, some are in the aquarium business as well, but I don't remember of any experts around.

Please post detailed info about your chemistry (calcium, alkalinity, magnesium), lighting, inhabitants (fishes, corals, etc...), additives, feeding, maintenance, how old is the system, filtration (skimmer/reactors/etc), etc... More picture, if possible...
Hopefully one of us will chime in and figure out what's going on there.
Good luck!!

Grandis.

 

[kurtwalk]

Thanks Grandis. I am new to this whole forum thing so thanks for the tips:

My 75 gallon tank / 30 gallon refugium is 2 years old. I have a variety of 10 tangs, 2 shrimp, several snails and crabs. For coral I have star polops, ricordia and zoanthids. I do a water change every two weeks. Here are my parameters as measured recently:

Nitrates: 10 ppm
Calium: 500
Carbonate: 9 dKH
Phosphate: .5
MG 1600
PH 8.2
salinity 1.022

In the refugium:
protein skimmer
phosphate reducer
turbo twist

 

[kurtwalk]

more pics

 

[A. Grandis]

Thanks for the info and extra pics.
I don't see anything deadly wrong with your polyps.
I don't think they have any type of bacterial infection.
It doesn't look they are melting. They actually look healthy to me.
Maybe they are irritated. Try look for small organisms among them at night and such.

The fact they are partly closed could have one or many reasons.
I would look into predation and irritation first.
Also make sure the water flow isn't too strong on those particular polyps.
Check if one or more of your 10 tangs are nipping on the polyps.
Tangs tend to "kiss" the polyps once in a while. I've got 2 tangs in my 75gal and they do nip here and there without any apparent damage. Sometimes I see couple "skirts" missing an polyps closed, but they grow back fast.

Water chemistry would be the second to look for in your case, I would guess.
You could drop your calcium to ~420, Mg ~ 1350, keeping Alk @9.
Salinity could come up a little, say @ 1.023/1.024. Some people keep it at 1.026.
So the chemistry could be affecting that particular zoa species that is weird/closed.
Nitrates @10 is the top limit. Many suggest nitrates @1ppm or less. My nitrates are undetectable. That has also to do you zoas' health/growth/reproduction. Doesn't hurt to keep nitrates a little lower, perhaps @5 or less, and see what happens. Maybe water changes will help that. I would think that with so many tangs in a such relatively small space to keep nitrates in check would be a very hard task for you. You need to do more water changes than normal and keep a good maintenance schedule. Make sure you're still feeding those guys with the right nutrition: algae based foods! Very hard!!

Those would be my first steps to try find out what's going on there.
I would assume you have no reactors running in the system and that you've got a good skimmer to help you out.
I'm not totally against reactors, but I'm not a fan of them.

Let's see what others would suggest.
Good luck!

Grandis.

 

[kurtwalk]

A. Grandis,

thanks for your reply. Typo on my part as the Nitrates are "0" not "10".

Water flow is in low spot right as of a month ago.

I do have fireworms that are prolific in my tank. I had an arrow crab and now a banded shrimp to reduce their numbers...but they like to hide in my coral and rock.

I have never added ca or mg...how can I reduce those levels?

Also, i can buffer my PH to 8.4 bit how in the world do you get it to 9?

as for food, I have used reefroids 1x a week and feed with phytoplankton 2-3 times a week.

the closed polops were once 3x in size and fully skirted a few months back.

 

[kurtwalk]

i forgot to mention that my tangs do sometimes brush up against the coral, but I have never seen them nip at any of my coral.

 

[A. Grandis]

A. Grandis,

thanks for your reply. Typo on my part as the Nitrates are "0" not "10".

You're welcome! Oh, good, then nitrates are OK...

Water flow is in low spot right as of a month ago.

I do have fireworms that are prolific in my tank. I had an arrow crab and now a banded shrimp to reduce their numbers...but they like to hide in my coral and rock.

You need to get the fire worms at night. They are bad guys for any type of aquarium with zoas! Be careful not to get hurt. I would get them out with long tweezers, one by one.

I have never added ca or mg...how can I reduce those levels?

Then forget about it. Make sure your tests aren't expired.

Also, i can buffer my PH to 8.4 bit how in the world do you get it to 9?

You wrote your pH was 8.2 and the dKH was 9. I was referring to keep the dKH (alkalinity) at 9, not pH.

as for food, I have used reefroids 1x a week and feed with phytoplankton 2-3 times a week.

Feeding was referring to nitrates. Now I know it's zero. The feeding contributes to the explosion of fire worms. Believe me they can irritate the polyps to the point of eradication because they will close and the irritation could cause secondary infection by bacteria. Our closed systems aren't like the ocean and the worms can get to outrageous numbers in the right conditions. Some of them can grow a lot too. Some species will prey on fish at night. You don't need them! They could be the only problem in your tank!

the closed polops were once 3x in size and fully skirted a few months back.

Try to remove as many fire worms you can tonight. You'll give them a great relief. Specially if they are reproducing in the rock you have the affected zoas.
Good luck and be careful!

Grandis.