If you are talking about the things that are kind of neon green in the pic then no, that is not Aptasia. Aptasia will present as almost clear to a darker red/burgundy. Tentacles will be thicker at the base and become thinner towards the top.
Hydroids
Drop a dab of gel superglue over them it kalk paste or at least try to starve them by aiming flow towards not at them to prevent food from reaching them