What is the best explanation

[Ken Good]

I have an SPS tank that seems to be doing very well until a couple of weeks ago. I have a 150 gal tank with a 30 gal sump. I am using the ULNS. My corals have been showing good extensions and lots of polyps. About two weeks ago, I noticed that a couple of my corals started closing up their polyps and staying closed. It has slowly spread to the rest of my corals. I changed out 25 gals with no affect. The last time I checked my parameters it was as follows: alk 8, cal 380, mg 1300. I am running GFO, but my phosphates were creeping up. I realize that I had not changed my GFO for awhile so I changed it. Also, I have been dosing Amino Acids for sometime at 2 ml, but have been infrequent. In the last month I purchased new Amino Acids and noticed that the old bottle the fluid had become discolored. I also started dosing 5 ml a day and doing it consistently. Finally, I have had a little problem with my Alk going up and down 7 to 9 and I think it is resolved now but I have not seen any changes in the corals. What is causing my coral issues: (1) the alk flutuations; (2) phosphates rising; (3) the AA dosing of 5 ml is too much to start; (4) a combination of 1-3; or (5) something else?

I think it may be the phosphate or the Amino Acid dosing. If so, it should resolve as the phosphates go back down. Also, I have suspended dosing of AA so if that is it there should be improvement within days. What do you think is causing my issues?

 

[neoalchemist74]

Mag is at the bottom end that would cause your alk fluctuations. Also you did'n't give your nitrate readings ,I'm assuming they are low w/denitrator. Did you change the GFO b-4 or after you noticed the problem?

 

[Ken Good]

I just changed the GFO Sunday which was well after I noticed the problem. Nitrates are less than 10.

 

[neoalchemist74]

Maybe check for stray voltage. Montis seem to be affected first by stray voltage. Polyp over extension is some times a symptom of carals that are under fed, could it be that the amino acids are satiating them and they are happy? Also make sure you don't have any nipping fish, flat worms, red bugs ect.

 

[Faisal1976us]

Maybe you have fish nipping on your corals !

 

[Ken Good]

I have checked for voltage and everything was in good shape.

 

[Ken Good]

I did get a new fish recently. If it was nipping would this cause the polyps to close?

 

[mutateddogbone]

check for redbugs or flatworms. what fish did you get?

 

[Ken Good]

It was a bi-color angel, but I have had them before without issue. I do not see any evidence of red bug or flat worms.

 

[mutateddogbone]

#1 suspect is angel. pull a chair up in front of your tank and sit there for 30 mins to an hour, only way to be sure is to catch him in the act. I had a flame angel and the same thing happened. was fine for 6 months then my PE went away. sat in front of the tank and sure enough, polyp nippin.

 

[redfishsc]

The alk fluctuations will be very hard on montipora species, I've noticed (sadly )

Also, the change from the old worn out GFO to the fresh new stuff may have been too much, too fast for the corals. You may have shocked them a little. Can you remove some of the GFO?

 

[buy_baff]

+1 on the angel. I to had a nipping flame ange

 

[Ken Good]

Update: Phosphates are back down to zero. Alk seems to be stable. Suspended dosing Amino Acids a week ago. No changes in corals. I am thinking more and more that it is the angel. Now to trap the little devil.

Ken

 

[Ken Good]

After trying many things I decided to trap the suspected fish to see if that was the cause of the problems with my corals. I trapped the fish today. I should know in a couple of days.

Ken

 

[BradR]

Baste the corals and see if any AEFW blow off!:worried:

 

[elijaher]

Keep us posted.

 

[Ken Good]

It has now been about 18 hours since my bi-color angel traveled off to another tank and the polys on my SPS corals are starting to peak out again. Should know more in a couple of days.

I will miss my angel. He was not eating at first and I thought he might not make it. But then he started eating mysis shrimp and then started eating seaweed too. He was always picking at the corals too. I have had several of these before I got corals and it has alway been difficult for me to get them to eat.

I will let you know more soon.

 

[Ken Good]

I am happy to report that my corals' polyps are starting to open up again. They are still going pretty slow, but I think it is at the point where I am sure that the problem was the fish. I would like to say thanks to everyone for their ideas. I did not think of a fish nipping at them. Neoalchemist74 was the first to suggest a nipping fish. Thanks again. The mystery has been solved!

 

[sslak]

Same thing happened to me. I rarely ever saw it nipping, but all my SPS closed up.

Ebili Angel removed = problem solved.

 

[JEFFR259]

I believe I heard once that new GFO needs to be slowly added into the system. Basically refilling your GFO system with new material all at once can shock the tank. I heard this before from my LFS but I never remember to slowly introduce new GFO when I refill. For a few days after replacing GFO my tank looks off (bad PE). Then all returns to normal. Seems logical to me in my setup at least.

Just bringing that experience up as you mentioned replacing your GFO