Acan reaction to changes in salinity

[Gatorbuilder]

Yesterday I noticed that my acan was not fully extended. Which was very odd because of all my young corals the Acan seemed to be one of the hardiest. Oddly enough all my other corals (Duncan, Zoanthids, Toadstool, Blasto and even the Ricordea) were all seemingly fine. So I did a full run of water tests just to see if anything was a miss. Background on the tank. it is a 11.5 Gallon rimless with virtually no serious filtration. It is several years old and has been abused at times with horrible husbandry. Yet over the past 4 or 5 months I have done some revamping on it and cleaned it up and gotten it back on track. I do bi-weekly 2.5 gallon water changes and run an Aqua Clear filter with nothing more than a bag of carbon and a sponge filter in it.

The water test results were:
pH 8.2
NH3/NH4 0
NO2 0
NO3 0
KH 8.7-9.0 (ran this test twice to confirm)
PO4 0.1 *still working on getting this down...
Salinity 1.021

The salinity was way out of whack so, I dripped in a higher level of salt solution for my daily top off. That had it back up by this afternoon, to 1.024. I am going to stop the drip now and get it up to 1.025 when I do my next water change Wednesday.

I post that info to ask this. Has anyone else ever noticed Acans reacting to low salt levels? I do love to find little tell tale system indicators like this. I always make notes when I come across little hiccups like this to see if they ever happen again. I hope to not let me salt get that low again to have to test this Acan reaction. But just wanted to see if anyone had experience anything like this before.
Today things seem much happier....

 

[Flippers4pups]

Yesterday I noticed that my acan was not fully extended. Which was very odd because of all my young corals the Acan seemed to be one of the hardiest. Oddly enough all my other corals (Duncan, Zoanthids, Toadstool, Blasto and even the Ricordea) were all seemingly fine. So I did a full run of water tests just to see if anything was a miss. Background on the tank. it is a 11.5 Gallon rimless with virtually no serious filtration. It is several years old and has been abused at times with horrible husbandry. Yet over the past 4 or 5 months I have done some revamping on it and cleaned it up and gotten it back on track. I do bi-weekly 2.5 gallon water changes and run an Aqua Clear filter with nothing more than a bag of carbon and a sponge filter in it.

The water test results were:
pH 8.2
NH3/NH4 0
NO2 0
NO3 0
KH 8.7-9.0 (ran this test twice to confirm)
PO4 0.1 *still working on getting this down...
Salinity 1.021

The salinity was way out of whack so, I dripped in a higher level of salt solution for my daily top off. That had it back up by this afternoon, to 1.024. I am going to stop the drip now and get it up to 1.025 when I do my next water change Wednesday.

I post that info to ask this. Has anyone else ever noticed Acans reacting to low salt levels? I do love to find little tell tale system indicators like this. I always make notes when I come across little hiccups like this to see if they ever happen again. I hope to not let me salt get that low again to have to test this Acan reaction. But just wanted to see if anyone had experience anything like this before.
Today things seem much happier....

Hard to say. If it's been use to lower SG and it's higher now, as it's possible with any corals, the change may have caused this.

As everyone will say, corals are okay with small/little changes. Stability is key.

 

[mimo91088]

My acan shrinks up every time I do a water change. But it always opens back up by the next morning.

 

[Da8]

3 points rise at a once is pretty hard for the animals.
Never do that again. It's better to rise every day a point.

Stability and slow changes... Quick and sudden changes are lethal for animals.

Don't worry about seeing a coral closed one day. It something usual. If more than one day, worry. But in this case, if it is because either the 1021 or the sudden rise, you can't do anything more than waiting.