I know that that should technically be the lowest flow area since it’s underneath the powerhead, but it’d probably do better if it were sort of shielded by a rock (like more in the front of the tank right in front of the rock work). Of course, you then run the chance of it growing onto the main structure, but if you keep an eye on it and detach any growths as soon as the touch the rock work, you should be able to manage it. But so long as it’s open and feathery looking and not being battered by the current, it should pulse. I know mine always stops pulsing for a couple days whenever I move it (I have a 28 nanocube, which is similar to the biocube, and I’ve had to move it a few times to find a spot where it wasn’t getting battered). I’ve also heard that iodine and magnesium supplements can help an non-pulsing Xenia start pulsing, but I don’t know how much truth there is to that. Also, there are Xenia species that don’t pulse (did you see it pulsing at the lfs or wherever you got it from?).
