Zoa's Melting

[snaza]

Hi Guys,

Have an issue where my most of my zoas are melting.

background.

tank 200g with frag tank (same water column)
lots of flow with tunze 6205
ATB skimmer
10x54 ATI PM

All params are in check and stable but has a bit of red hair algae stuff. Po4 was 0.00-0.02 on hanna but still had bit of algae to increased my Rowa phos. 1/2 cup. 2 weeks later all algae gone but zoas started melting. a few patches are ok but lots of them are completely gone.

I moved some zoos from my frag tank which has less lighting (still t5's) and within a few days they were gone. they just shrivel up and melt. I assume its shock because of the lightly change and extra par but i never had this issue before running the extra rowaphos. I tried some from my frag tank at the edge of my dispay (out of direct light) and they seem ok.

why are the zoas so light sensitive now? because there is less P04 there is more light???

all other coral and fish are fine

any help would be great

cheers

Aaron

 

[A. Grandis]

The removal of excess phosphates by ferric hydroxide products won't normally change the light (including PAR measurements) enough to bleach zoas.
The compounds that are removed by activated carbon are the yellow dissolved organics and that would make some difference in regards to light. Depending on the amount you introduce in the system and depending on how yellow the water was, they could hurt and some bleaching could occur.

I would remove the ROWA phos immediately and do a 10 to 20% water change, leave the tank for a week and see what happens. Many times here I've been posting against Ferric hydroxide products and how they can be bad to zoanthids (and corals too!), but I guess people don't listen. :hmm5:

I wouldn't add any supplement nor medicine to the tank to try fix what's happening because it's probably the ferric hydroxide. Water changes will begin to alleviate some of the stress and chemical responsible for the melting. They will probably take a while to come back but it can happen. First step is to take the ROWA phos out.

Some melting are from bacterial infections and if you introduced any zoa without dipping and that zoa was the first to melt, than I would think it could be a bacterial infection. If you didn't add anything new in the system and it happened, as you've said, after the ROWA phos, it has a low percentage to be any bacteria.

Another reason for melting could be poor light quality (PAR only wouldn't matter!) and/or very low nutrient system.
Would be interesting to know what bulbs you use for your system.

Keep your skimmer running. That is a good skimmer, isn't it?
Your T5 ATI light system too. Both are very good choices!

Hard to know if your parameters are ok if you don't post them here.
How good is good?

Pics?

Grandis.

 

[snaza]

Thanks for the reply Grandis.

Yeah the skimmer is good.

got a mix of AB and B+ ATI bulbs

Params are;

Salinity .026
Alk 8
calc 420
N03 - 0.05
P04 0.00-0.01

nutrients are pretty low.

I'll do a water change today and remove the Rowa

cheers,

aaron

 

[A. Grandis]

Yep, params are fine...
You've got a good bulb combination!

I assume you did change the bulbs slowly and, as you did in the past without any major problems. The addition of ROWAphos was the mistake then. Specially while changing bulbs.

I would recommend to get some of the old bulbs back in the fixture as well to help the zoas out... Perhaps 50% of what you've changed already and start changing after you see some improvement with the zoas.
Good luck!

Grandis.