Algae problems

[dinod73]

I have algae growing like crazy... Been fighting it for months. At one point pulled rock out to scrub it clean. Still growing. Recently added 12 hermit crabs to the tank. My tank is a 40 display with a 20 gallon refugium. I have 2 clowns, 1 goby, urchins and a pistol shrimp... Any suggestions please

 

[chefjpaul]

https://www.reef2reef.com/threads/reef2reef-pest-algae-challenge-thread-hydrogen-peroxide.187042/

I'd quite adding creatures and get to sources; detritus, rocks, nutrients etc.