This Algae is driving me crazy

[Carz]

I am going to try to keep this short.
I had a few fish show some signs of Ich several weeks ago and I moved all of the fish into QT my main DT is 75 gallons with a 20 gallon sump. The DT contains 2 hammers, 1 frogspawn small GSP, 3 mushrooms and 4 zoas. I also have a red bubble tip and 3 pink bubble tips and there is a a good variety for my clean up crew. The tank has been fish free for 3 weeks and I have not fed anything since then. I had some hair algae and I turned my lights out for 3 days and did a big water change after that. Things looked great for 4 days and the algae is slowly returning

My problem is this algae growing on the sand, glass and power heads. My API test kit reads
Phosphates = 0
Nitrates = 0
I am running a GFO and Carbon reactor and a protein skimmer.
I have 2 360 Kessils that are on a schedule for 12 hours which I just changed to 8 hours today.

about 2 weeks ago my red bubble tip split and ended up in the wave maker and got chopped up and I got most of it out.

This is my story and just cant seem to understand why I have algae when I am not adding any . types of Nitrates to the system. Any thoughts???

 

[Jesterrace]

The lighting was definitely a factor. You may have to kill the lights for a few days again to get ahead of it. 8 hours should be max.

 

[saltyfilmfolks]

The green on the rock I see looks like the beginning of corraline algae.

Doesn’t look like hair algae

The brown looks like diatoms , maybe a Cyano. Color is weird.

Use caution stripping the phosphates to zero with gfo.
Bad things can happen.