Based upon the apparent size, color, and reproduction rate you might want to pull up a few photos of Majano anemones. Many folks consider them to be pest anemones like Aiptasia, although they typically are far more attractive and often have neon green shading. If they are e. quads, they will likely get larger (3-4") before splitting, and these all look like they are under 1.5 - 2" in diameter.