My duncan coral colonies

[vortex9]

Flow's definitely a possibility, and I've had my own issues with an emerald crab and a duncan colony. I had to get rid of the crab, it was occasionally cutting tentacles off the polyps. The duncan never got used to those 'haircuts'. Parameters and light seem fine to me.

[luremate]

I've got it positioned under a power head in a corner, and it's open now, but it doesn't quite resemble the typical pics I've seen or its original appearance when I first picked it up. The pictures I tried taking all came out blurry, unfortunately. It seems I've placed it in a low flow spot, as there isn't much movement.

[flametop]

Give the duncan a bit of time, I'm sure it'll come around. Mine seemed to grow bigger every week, took a while to fully open up though.

[luremate]

Two shots of my Duncan - one with the lights on, one with them off. Different angles too. Sorry for the poor quality pics, I'm still getting the hang of using my old DSLR again after a long break.

[axonify]

Duncans can be quirky at times, maybe try feeding it some mysis and see how it goes.

[vortex9]

Here are a couple of pics, one with the light on and one without, different angles too. Sorry again for the bad pics, haven't used my old DSLR in ages.