Acan mood swings?

[sillysidewinder]

So two of my favorite acan colonies have been acting a little strange the past couple of weeks. Up until 2 weeks ago they were huge and inflated and seemed insanely healthy. I was spot feeding them everyday and they loved it. Here is a photo from then:

For the past 2 weeks it seems as though they've been going through some kind of a mood swing. They open during the daytime and close when the lights are out. However, they don't open nearly as much and I'm not sure why. There's a couple of other acan frags nearby that don't seem afflicted with the same signs. Here is a photo of what they look like tonight.

Anybody have some input? I don't want to move them around or anything like that because I know that they have been happy in the position that they are in.

 

[basiab]

Mine don't show any tentacles during the day. After lights are out then they come out. All corals seems to have cycles where they open nicely and then for a while don't. Even when there is no changes in the tank. However sometimes things change without you realizing it. Bulbs get weak, glass cover get cloudy, a couple water changes missed. I feed mine only once a week. I use frozen chopped up silversides. What do you feed yours? Just because a coral ingests something does not mean it get something out of it.
Dried foods that fish eat is fine for them because they have a real digestive system. But corals probably don't get much from them since their systems are very crude.

 

[yesjenks]

Did you change something in your lighting? The first picture looks much brighter than the 2nd.

 

[Oholic]

The 2nd shot looks like his lights are off... maybe moonlights... only b/c he said "Heres how they look tonight"

 

[FaviaFreak]

acans like a little nutrients in the water (amino acids) help bring out tentacles and puffiness 24/7

 

[yesjenks]

The 2nd shot looks like his lights are off... maybe moonlights... only b/c he said "Heres how they look tonight"

True, good catch!

 

[Jakef150]

Or shrimp might bothering it. I caught one of my shrimp ripping off acans and eating! So I had to get rid one of my shrimp

Jake