You're welcome, that all sounds good. I have used the trick before, with turning up and down the lighting, to see if newly introduced nem had energy left to move. If nothing else, it offers some piece of mind for the owner to see the nem move alittle.
And the macrodactyla doesn't look too bad, I would try to not be concerned yet. They do, especially the smaller ones, tend to be a bit slow in getting organised.
I guess it will want to "know" how the currents are acting in your tank before choosing how to arrange itself. Since the ocean would offer a lot more diverse currents than in our tanks, this type of nem seem to take its time before figuring out how to arrange everything. I have seen videos of macrodactylas in the wild dig their foot in kinda fast but it seems to go slower with the ones we get from the shops. If it seems to be getting its foot into the sandbed, then just give it time.
I think if it literally does not dig into your sandbed even at a slow rate, it may be waiting for a sudden strong ocean current to push it to a better location.
From what I can tell they prefer locations where the current has a circular motion around them, rather than somewhere where the current flows past them from one side to another.
But I definitely think that these types of nem are slower acting than BTA types when it comes to settling down. Macrodactyla does not seem to actually "crawl" around a lot, except to just adjust a little. And if I ever change anything about the direction of the flow in the tank I keep, the macrodactyla always reacts with pulling everything in and rearrange itself to the flow before it unfolds again completely.
I hope that your sad little jelly flower is going to look happier soon, they can be so stressful to their owners when they act out. But you probably do not need to worry at this time.
