My Acanthastrea Feed

[Horsehead_kor]

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indonesian rainbow acanthastrea

8 kinds food mix

[Moort82]

I'm sorry but that doesn't look like a feeding response to me, its also not particularly happy imo as the polyps are fairly retracted hence the skeleton between them. You normally see the polyps puff up and the tentacles come out. I think what you are seeing is the response to the food being blasted at it. Try to let the current waft the food onto the coral and you will get better results.