My 40g reef is about 3 months old, started with established rock and large GSP colonies. Currently dealing with algae growing at an insane rate which has begun choking out my corals. I have been brushing and siphoning the algae near daily, but it just reappears overnight. The GSP seems to be melting in places which is also concerning. Phosphates are undetectable, and Nitrates have been a stable 5ppm since I got a skimmer running. My current plan is large water changes combined with a 3 day blackout, also considering starting dosing Vibrant. It looks like Dino mixed with Hair Algae, I am new to the hobby though so would appreciate any input with identification and treatment. Thanks all!