color changes in sps (fade) but growth is ok??

[chindapol]

Assume other parameters are pretty stable. I placed one of the wild collected colony directly under 150MH. After one and a half month, the color fade out noticeably but growth is awesome. Pic included but not very clear. Any thought?

 

[icliao]

1. Time = It takes time to a wild colony to return its color, give it at least 2 months.

2. Lighting = Too bright you get too light color, too little you get brown shades

3. Nutrient (NO3, PO4) = If it is detectable, you got too much and you will get dark shades or brownish color. Especially phosphate.

4. Coral feeding = too some degree it helps if 1 - 3 are met.

Of course there are always exceptions for some colonies but I believe they are general important things to look at.

I have friend with 12 ppm NO3 and 0.2 ppm PO4 but a few of his acropora colonies are showing beautiful colors. (Unfortunately only a few of them, most of the acropora assumped dark/ brownish color in his tank.)

I hope the information is helpful.

Good luck!

 

[chindapol]

Thanks icliao for your advice:

I have acro on the edge of the light figure that show superbly brown color and almost dark on the very far out. Some nasty algae showing up on the rim of my plastic pond. The pond dimension is 48''x33''x17''. I lit only 2 MHs. The darker one are on the edge of the light figure.

I never test the nutrient level but assume it's quite high (since the growth of nusiance algae) Probably indicate that it is because of the light and a little too high nutrient level. (I am using Phoenix TDB (blue) bulbs)