HELP - Why am I losing Acan colonies?

[mspad]

I am starting to lose several acan colonies. I have checked the following parameters:

Specific gravity: 1.023 - 1.024 (refractometer calibrated)
PH: 7.9 - 8.2
Calcium: 400 - 420
Temp: 78.1
Phosphate: <0.05
Nitrates: 0-2 ppm
Alkalinity: normal
Water: RO/DI water (Filters up to date)
Lights: (4) 175 watt halides, (4) 96 watt PC's Acans at bottom of tank, colonies have been in this tank for years. Lights changed once a year, at different times.

I don't get it. I have taken a close look at the colonies and cannot see any bugs. The acans start to recede from the outside and work inward. It makes me think that it has something to do with water chemistry.

Any suggestions?

 

[Dave VG]

What kind of flow are they getting? Mine like pretty good flow. I tried them in a lower flow areas and they shrink. Put them back and all is well.

 

[pascal32]

I believe you should be at 1.026 for SG (35PPT) - the slight difference make a big difference.

Any recent changes? any recent large water changes? Possibility of chemical warfare - are there corals close together? Are you running carbon? at night shine a flashlight - are there any predators?

 

[5380]

Mine appreciated a little extra light. I replaced my mh and set it for 7 hrs. I also cut down on my skimming and bumped up feeding. Like you my sg is a little low. I was losing them so quickly I just threw up a hail Mary and changed everything. As it stands now I lost 2 and revived 2.

 

[iamwrasseman]

consider a treatment of interceptor just in case they are infested with some tiny critters as they are to small to see and it happens to acans .i have had this exact thing happen to my tank and the interceptor worked miracles for me .

 

[cardiffgiant]

I didn't see a magnesium reading listed in your parameters. Acans use magnesium pretty quickly. You could be low (under 1300), especially if you're specific gravity is below 1.026.

 

[NirvanaFan]

what is your normal reading for alkalinity?

 

[cardiffgiant]

Ah, I didn't catch that. The first Kh test that I bought was a red sea combo for Ph and Kh. It had three readings for Kh: high, normal, and low. I believe that the readings were a range in meq/l and that normal would have translated to anywhere between 5 and 7 dKh.

If that's the test kit that you're using, I'd take a water sample to your LFS to have them double check, and consider picking up a salifert Kh kit.

 

[RandyO]

First thing I would look at is specific gravity. Something so simple, yet so important.

As someone else has said, Acans like Magnesium levels at 1350 ppm and it's very difficult to keep those levels that high when there's not enough salt in the water.

Try raising your specific gravity to 1.0265

Chances are you will not see results quickly, since the damage has already been done. I usually dip the Acans in an Iodine coral dip to help prevent infections while they loose flesh around the edges. Most of the time the recession is slow. But I've seen them get brown jelly infections while they recede, and then the whole coral can be lost in a few days.

 

[Paradiddle7]

I'm not sure about Acan's but some corals also do poorly if any of your parameters fluctuate rapidly. I've had some corals die because of an ATO failure where my salinity went down quickly, even though I brought it back up slowly.

 

[mspad]

First, I would like to thank everyone for the extremely helpful information.

Last night I was lucky to find my Interceptor. So I had to remove all of my shrimp and hermit crabs to another tank. I completed this process around midnight.

The SG is now 1.025 and plan on raising it to 1.026 I had initially lowered the SG because it was at 1.027 and I was still losing acans.

Mag (1200) was tested this morning. I plan on raising mag to 1350 today

Carbon was changed 2 weeks ago, It has been removed because of the Interceptor treatment.

My acans have medium flow.

No corals have been added to this system in over 3 months.

I plan on dipping any receding corals in Iodine.

I will post outcome in a few days. Thanks again for the help.

 

[mr86mister]

Wow, fantastic advice from the members here. I would agree with all of them on possible variables in your issue.

 

[block head]

that red sea test is sketchy . 8.0 (sailfert) = light yellow/low on red sea.

 

[RandyO]

I wouldn't raise the Magnesium 150 ppm in one day. JMO. Most Magnesium supplements recommend 15 ppm/day.