Thanks bud, it's extremely frustrating. I've tried really all of the basic stuff to fix this with no luck. I don't have a phosphate test kit but I have had some lfs' test and it's always been zero. Also I have tested my nitrates and my girlfriends nitrates and mine always come up undetectable while there's some detectable in hers. So I am gonna run up to what most would say the most reputable lfs in the area and consult their help.
Red LEDs do not cause or encourage algae growth like you guys think.
I can (and did) grow GHA by the pound in my sump with bright white LEDs because my nutrients were too high. If you took a reefbreeders fixture with all red LEDs and put it over a tank with low nutrients, you wouldn't see GHA. Likewise, if you took all of the reds out of said fixture and put it over a tank with high nutrients you would see an explosion in GHA growth.
That's why Icthyman and other more experienced hobbyists are saying to target your nutrients. Once you target your nutrients, your problem will go away.
To tackle my problem (high nutrients), I did this:
1. Cut feeding and used pellets and frozen vs flake
2. No coral food: Fish poop and leftover food is plenty for your tank. The only time you absolutely have to feed your corals is if you ran a ultra low nutrient system, and then you wouldn't have a problem with GHA in the first place.
3. Filter socks (for nutrient export)
4. a bigger skimmer (for nutrient export)
5. a small amount of biopellets (or another carbon source) for nitrates
6. GFO or ROWA for phosphates
7. Took out my phosphate loaded rock and acid washed it to take out built up nutrients
Trust the people telling you to target nutrients and you will be successful, I sure was.
Finally, I only do/did the three days of dark for a cyano outbreak, not GHA which can live in a trash can in summer for a few weeks without dying (seriously).