SPS closed up

[Max1]

Hi, I have a Red Sea 625 reefer,
I have a mixture of corals, including some sps at the higher light areas of tank, they where going good but in the last around 10 days they have closed up, I haven’t changed anything major, I do regular water changes of around 7% and do maybe 2 a week so average 15%. Only thing that I have changed since noticing this is I have decreased the amount of time between dosing for Kh. I keep my Kh 8-9, and before I would give it a few days and then test, and it might be at 7.8, so I would dose it back up to 9, then give it a few more days and check the drop and dose again. I know that raising it by 1 on a regular basis isn’t the best so I have changed and now dose daily, so a rise of around 0.4 at a time. Any thoughts or opinions on why they are closed? They looked good and had some growth when went into the tank, so I don’t think the lights are too bright. I put Red Sea AB+ in daily, but I don’t feed phyto, just brine shrimp and coral food occasionally,
My nitrate I keep around 8-12, and phosphate at 0.09-0.12 is what it sits at.

 

[Mr. Mojo Rising]

Can you advise what you have for light and flow? sps like light and flow much more than pally's, so seeing them at the same level gives me an idea the light and flow might perhaps not be enough.

 

[Reginald Reefer III]

If all other major/minor tests are coming out OK, what I have seen in acropora is that a very high level of volatile organics in the water causes minor or even major polyp irritation. Dissolved Organic Carbon aka DOC/SAC254 is often overlooked and is usually the main cause for things like algae/cyano/unwanted or toxic bacteria/coral irritation. I use a specialized catalytic activated carbon (CAC) and pretty much run that 24/7 to keep levels low.

If you haven't done an ICP-MS test, I would maybe start there and see if that sheds some light on the issue. Don't get an OES to start - it's not nearly detailed enough to accurately get a good baseline.

 

[nautical_nathaniel]

I think I might have found a clue:

(Not saying that's the issue but I found it funny the clown Goby was just sitting there on an upset coral )

 

[Reginald Reefer III]

I have fish sitting in my acros all the time. Might close up for a bit, but will open right back up. What other fish do you have in the tank? Some fish develop a taste for acro polyps and will peck on them day and night.