Hi,
Definitely check the texture of the tube - is it hard, or soft (you can just use some tongs or the like to gently tap it). If it's soft, then it's either a tunicate or sponge of some sort - either way, you're in the clear. If it's hard/more stiff than soft, it's either some sort of tubiculous polychaete or a vermetid gastropod - again, no worries as it doesn't appear near any corals that its feeding appendages/webs could irritate. Judging by the color and near translucency, my guess is a tunicate or sponge. Tube-dwelling worms and vermetids have walls with a more opaque, leathery, or parchment-look, sometimes covered with bits of rock, shell, sand, and other debris, or they're calcareous. Bottom line is that it took a paragraph to say the same thing that Cubbies already said - it's a keeper - no worries!