Why my corals are shrinking?

[nemokit]

Need some advices from experience reefers... I finished cycled my tank and slowly added some coral (LPS, anemones, branches...) into it...The first few days the corals seem ok to me except that it did not really open up as what I saw in the first fish shop. So I thought that they have not aclimate themselve in my tank.

A week later, some of my coral starts shrinking in size (dieing...) and some just remain unopened... I have checked all the reading such as PH, PO, NH, NO and all gives promissing results (Except my Nitrates read about 20ppm). Check for Copper and found 0 trace. My Calcium level is arount 550, and am using 2 x 250 MH (10k) light for my 4 x 2 x 2.5(depth) tank. My aquarium chiller is set to cool at about 27 Degree.

Could it be the high calcium level or too much of light intensity that causes these? My fishes (crown fish) were all right. It is very disappointing to see them fading away...

[cityofangels]

How long have you had the corals? And could you perhaps, provide a list of the corals which are not doing well in your tank?

Calcium levels are best around 350-450ppm. Hard corals essentially need calcium for growth. And because of your high calcium levels, there is a high tendency that your alkanity levels may drop.

Besides the clown fishes, what other fishes do you have in your tank? Some fishes are not reef-safe and tend to peck at "fleshy" looking corals.

It would be best to provide a pic of your whole tank. Certain corals like high flow water, whereas certain corals like medium or low flow water. Perhaps, we can help you plan where to place certain corals in your tank when we see the whole picture.

[FuEl]

Too high calcium level. Happened to me before. Perform water change asap to lower the Ca level and stop adding any calcium additives. If you have nOt been adding any it might be the brand of salt. Change to a new brand if so.

[nemokit]

Ok, I will get some pictures and put it here...