Hello Chin,
It works great at getting rid of Red Slime algae. It's reef safe and treats 300 gallons for a very reasonable price. I used it for years when I did aquarium maintenance.

One thing to mention.
If you don't get rid of the original source/cause of the Algae problem, it will eventually comes back.
https://www.oceanaquatics.com/view_p...uct=CHEEIQI012