How to get rid of this stuff

[Ashley13]

So i had this stuff slowly show up in my tanks sandbed a while back and there was small patches of green hair algea on some places of the rocks and other small patches of green slime. (Slime came off easily with a brush but would come back in a few days) I was advised to manually remove hair algea (got what i could but it was very short and hard to grab), suck up algea/waterchange, dose chemiclean and do a 3 day blackout. I did this and it helped. But sandbed never got fully white again, there was still small areas. After doing that for the last 3 weeks I've been doing 10-15 gallon water changes once a week sucking up the sandbed but within a few days it comes right back. Any ideas?

My lights run 3pm-11pm.

The peak is 4:45p-7:45p which is this..

Then at 7:45 it starts the go down and at 9:30 it's looking like this..

My question is, is my lighting schedule good or is it contributing? BTW fish and corals seem happy.

 

[blaxsun]

I'd temporarily drop your reds to zero if you're having algae issues.