Angry Acans - Can't Figure it Out

[rrasco]

If anyone has listened to me talk about my tank in the last month or two you've undoubtedly heard me complain about my acans.

Here's the short version, if I may:

I have a nice 10 head colony and several smaller frags of acans. The large colony came from my old tank and has absolutely thrived in the new tank, under LEDs. I added a few more frags that were kind of beat up from being fragged, but showing plenty of signs of improvement. These would all have significant polyp extension during the day with feeder tentacles out. They would close up but continue to extend their feeders at night. That all changed a few days after I began running GFO and GAC, close to 2 months ago. The GFO and GAC did its job. Water became crystal clear while algae and sponges began to recede. Everything else is literally happy. Softies, LPS, even the SPS I have are showing growth, good color, and decent PE at night (they are still relatively new though). However, my acans simply will not extend their polyps anymore. They still extend feeders at night and I have noticed zero tissue recession. They look healthy, just not opening up.

At any rate, I've effectively isolated the acan disturbance to when I started running GFO/GAC and I have two theories on what is upsetting them.

1) The carbon increased water clarity thus increasing light intensity on the acans. Likely, but I'm not sure since other LPS right next to them are doing okay. This includes chalices and favias.

2) The GFO/GAC is working too effectively and making the water too clean. Although, I am only running half the recommended amounts for my tank, I am leaning towards this as the cause.

I've tried:
-feeding more
-moving the acans to shadier areas of the tank
-turning off skimmer during feedings (just made my tank cloudy)

I know everyone wants to know params, so here they are...

SG: 1.025
KH: 9.0 dKh
MAG: 1400 ppm
CAL: 430 ppm
Nitrate: 10 ppm
Phos: Undetectable on Hanna, but there is some algae
Temp stays 76-78

I am dosing 70ml BRS 2-part daily (I don't dose mag daily, am I supposed to?)
I do 5 gal weekly WCs with reef crystals

Any ideas?

[hobogato]

the times i have seen this happen to acans, it was always one of the following:

1. temp - this doesnt seem like your issue considering your posted parameters
2. too much light - acans dont like sunlight very much - might be your issue, dont judge based on success of chalice or favia as they can sometimes handle more light
3. something picking on them

i am not saying it couldnt be something else, that is just my experience.

[rrasco]

I did lower my LEDs a little bit 2 days ago. No change yet though.

I have not ruled out something picking on them. I've seen my flame angel 'mouth' several corals, but normally just new ones and only for the first day. Maybe I need a camera.

[hobogato]

here is my list of fish that have picked on acans (along with other lps) in my tanks over the years: flame angel, coral beauty, tangs (yellow, hippo, vampire, sailfin, purple), lined blenny - and that is even tho i feed three times a day and add nori to the tank. i would definietly be suspect of that angel.

[rrasco]

He almost got yanked already. I added some SPS a few weeks ago and he was going around to each one investigating. I think I'm going to pull him and throw him in the FOWLR and hope my shark doesn't view it as a $30 meal. Maybe with him out of the tank I will see some improvement.

[Big_Pun]

i stop running carbon on my tank 3 months ago to see if all the hype on RC was true about carbon like rox being too powerful....... polyp extension has been better but nothing else has changed, i still run gfo and tank is crystal clear. may be start there

[rrasco]

I am also running ROX, so maybe so. PE on your SPS was better? I usually don't run carbon on tanks, but with the possibility of allelopathy I feel safer running it on the reef.

So many variables!

[hobogato]

we run carbon on christy's 29 that is packed with acans and they seem to be doing great.

[Big_Pun]

we run carbon on christy's 29 that is packed with acans and they seem to be doing great.

rox ?

[EpicWin]

If anyone has listened to me talk about my tank in the last month or two you've undoubtedly heard me complain about my acans.

Here's the short version, if I may:

I have a nice 10 head colony and several smaller frags of acans. The large colony came from my old tank and has absolutely thrived in the new tank, under LEDs. I added a few more frags that were kind of beat up from being fragged, but showing plenty of signs of improvement. These would all have significant polyp extension during the day with feeder tentacles out. They would close up but continue to extend their feeders at night. That all changed a few days after I began running GFO and GAC, close to 2 months ago. The GFO and GAC did its job. Water became crystal clear while algae and sponges began to recede. Everything else is literally happy. Softies, LPS, even the SPS I have are showing growth, good color, and decent PE at night (they are still relatively new though). However, my acans simply will not extend their polyps anymore. They still extend feeders at night and I have noticed zero tissue recession. They look healthy, just not opening up.

At any rate, I've effectively isolated the acan disturbance to when I started running GFO/GAC and I have two theories on what is upsetting them.

1) The carbon increased water clarity thus increasing light intensity on the acans. Likely, but I'm not sure since other LPS right next to them are doing okay. This includes chalices and favias.

2) The GFO/GAC is working too effectively and making the water too clean. Although, I am only running half the recommended amounts for my tank, I am leaning towards this as the cause.

I've tried:
-feeding more
-moving the acans to shadier areas of the tank
-turning off skimmer during feedings (just made my tank cloudy)

I know everyone wants to know params, so here they are...

SG: 1.025
KH: 9.0 dKh
MAG: 1400 ppm
CAL: 430 ppm
Nitrate: 10 ppm
Phos: Undetectable on Hanna, but there is some algae
Temp stays 76-78

I am dosing 70ml BRS 2-part daily (I don't dose mag daily, am I supposed to?)
I do 5 gal weekly WCs with reef crystals

Any ideas?

You aren't going to like this answer but it is an experienced reefers reality. Some corals just don't grow in certain tanks. I have had many acans and have often had frags just fizzle out in tanks that are thriving. Stick to what grows well in your tank