Looking for some help - Refuge question and green hair algae

[Thoax]

Hey everyone looking for help, I have been battling this green hair algae now for a few months. I am not sure what els to do at this point.

I have tried cutting back on feeding once a day and very little, blacking out the tank for 3-4 days, Only using t5's for light for a few hrs, I had tried chato and that seemed to dye off not sure if was just was my light that killed it ( i could not get it to tumble in the sump )

I got a blue tuxedo urchin and he cleans everything other then the green hair, I have also gotten a foxface he's still new to the tank 2 weeks in and i don't see him touching any of it. I also have a purple tang/ sailfin tang/ blue eye tang and a hippo and non of them seem interested in any of it. Also tried phosphate RX no luck.

2-3 weeks ago i bought 2lbs of sea lettuce from algae barn to try and out compete the hair algae but it doesn't seem to be working

I am so lost lol, I have checked all my parameters and they all seem good and the No is reading 0 but they are deff there if iv got all this green hair in the tank.

The tank is a 200G system ( 140g display - 60g Sump )


This is an older pic and the hair algae is much worse.

 

[T-J]

What's your Phosphate levels?
If you're reading 0 on Nitrate, I'm guessing the algae is consuming it as fast as it's being produced. Are you manually removing it? Have you tried Turbo snails?
As a nuclear option, you could try Vibrant.