Hello,
From the photos, I assume that you don’t have any corals in the tank, right?
If so, it is very easy, just turn off your lights for 2 days… after that, set them (if possible) to the minimum.
You can also keep it off and just use the room light… that will be mostly to feed your fishes.
In case if you have a small coral frag in the tank… it is easier to bring to your local store and pick up again after the problem is solved.
If you cut the lights… normally it is solves rather fast.
Still, it might be good to put some snails when you bring the light back.
Let me know if it is all clear!