Is This Normal for an Acan?

NickNiz · Dec 22, 2016

Hello all! I recently set up a 12 gallon nano cube and have been adding LPS to it over the last week. I have an acan coral (my first) that I'm sort of worried about... Several of the polyps look great, but two (in the bottom of the picture) seem to be receeding? I shouldn't be able to see the skeleton like that, right?

As far as feeding goes, they get whatever mysis shrimp they can catch (not target fed), as well as 1.5mL of Red Sea Reef Energy A&B every day...

Here's some tank info...
Livestock

Clown Fish
Cleaner Shrimp
4 Nassarius Snails
Frogspawn
Emerald Eye Favites Coral
Acan (pictured)

And water parameters (from what I'm able to test using API Reef Master)

Nitrates: <5ppm
Phosphates: <5ppm
KH: 9 dkh, somewhat uncertain as I'm not sure I did the test correctly.

Corals are in low/med flow and on the sandbed. Nano Cube has LED lighting and an added custom blue LED strip. I appreciate any help!

NickNiz · Dec 22, 2016

And a full tank shot if you think it could be sweepers from other corals.

ChiCity · Dec 22, 2016

Acans will sometimes recede into their skeletons if bumped by something or to drop a deuce...
But yours, especially those bottom two, look like they might be bailing out

Is there a bunch of flow hitting that particular area?

NickNiz · Dec 23, 2016

Thank you for the quick reply! It's hard for me to determine flow but I'll try rotating it and see if anything changes... the only pump in the tank is the filter outtake, and both the frogspawn and brain have roughly the same current as the acan and seem to be doing well. Could it be too much direct light? I would try building a shaded spot for it but my LR pieces aren't ideal haha...

jenreefer · Dec 23, 2016

Your nassarius snails may be bumping it at night in search for food. that is a lot of them for such a small tank and they are brutes. Just a thought.

NickNiz · Dec 23, 2016

thanks for the input!!! I think I might've found out what was happening... I think I may have been putting too much Reef Energy into the tank. My LFS told me that if the stuff comes into direct contact with coral, or if too much is put into the tank, then it can burn and bleach a coral... Gonna reduce to .5 mL a day for a while and see if things improve.

In case it is lighting or flow, I put more LR into the tank and made an arch structure for the Acan to sit under. Also did a 3.5 gal water change to somewhat remove any excess reef energy that might be in the system...

On a side note, if it is too much lighting that's causing this, would reducing the light cycle from 10 hrs to 8 hrs help at all?