Need Help with Hair Algae!

[ReeferHead47]

I had the same exact problem in my 175 gal peninsula reefer, every rock I have was covered with about 1” of GHA. I have 12 small to medium sized fish with SPS and LPS so I have to feed heavily. I started a 1/4 lb ball of chaeto in my refugium and added a Kessil H380 light on a 10 hr cycle 9” above the water line. Make sure you add iron and iodine for maximum growth (+test). Along with my Vertex skimmer that took care of the NO3 and PO4 problems (+ high capacity GFO). Second my display lights (Radion G4 Pros) were set incorrectly with too much white spectrum and too low of intensity. I changed it to the CoralLab SPS AB+ with a PAR level of 280 for most of my SPS. Third and the most helpful, I added 6 medium sized pincushion urchins. They devour hair algae (and coralline) at an amazing rate. This all worked for me, good luck man! Oh and I have a Penatair 50 watt HO UV sterilizer and it works wonders for my fish but not sure about the corals (it’s keeps the water very “clean”).

 

[Toomnymods]

My rock was dry rock from marcorocks..

 

[Toomnymods]

just as a update.. I took all 200-250lbs of my marco rock out of my tank and soaked each rock in 100% 3% hydrogen peroxide for 5 mins each. scrubbing the entire rock. It was really fizzy and foamy and looked like pea soup as the hydrogen peroxide was dissolving the hair algae :) then I dipped each rock for a minute or so in some clean tank water, then back into the display. For 3 days I dosed Korralen zucht biomate, coral snow, and Zeostart 3 ( to remove phosphates) 95% of the hair algae was immediately removed and killed, and now after 3 days the remaining 5% is totally gone without a trace. Its such a good feeling to be able to see my live rock once again. I also performed a 90 gallon waterchange immediately after putting all the live rock back into the display tank.