That Aiptasia sure is big. Just about as big as they get. With only that single critter, I suggest you take extra precaution, remove the rock, kill the anemone with a mound of salt placed atop it while out of the water, clean well under saltwater (initially ensuring the water rinses directly off the rock, not over it), and replace it. As mature as it is, I would assume it has the ability to spread rapidly.
These are not benign creatures in the home aquarium left unchecked.
The same goes for that macroalgae.
If those bubbles get distracting remove the air intake hose. Gas exchange occours mostly at the air/water interface, that powerhead may be better suited aimed at the surface to increase the amount of water that comes in contact with air, maximizing gas exchange.
(Otherwise) The tank looks good!
HTH
Tim: