Algae is kikkin' my butt ?

[TANGOMAN]

Those of you who have met me will know why I'm bald ! It's because I'm constantly pulling the hair out of my head trying to control an algae problem in my 90g. Ironically, hair algae. Or a form of it. It is much "finer" than what I've seen over the years.
I've got two tanks goin'. The other is perfect. Same water supply and parameters. I was certain the 90g was suffering from lighting problems. Wrong. I had replaced the two 55w PC's (10K) and added 2x 40W NO Actinics. Pulled all the hairy rocks and scrubbed 'em. (this process surely had nothing to do with a form of parasitic irritation the fish suffered from). I began growing Caulerpa in the sump on a reverse photoperiod. I ran the tank for two weeks with no PC lighting. Things looked good and then wham, it's back with a vengeance.
With a lionfish there is no "clean-up crew", a Lemonpeel Angel and a stupid Damsel are the other occupants. Bio-load I feel is low to moderate. Yes, lions are messy eaters but the other two clean up awesomely behind him.
Rocks I'm thinkin' may be the problem ? When I bought this tank used several years back it had some live rock and a lot of "lava rock". Ya know, the pieces with big holes in it that's way over priced. I removed some of the lave rock and added live rock.
Should I "junk" the lava rock. I once read natural elements could be present and leach out over time...hmmm. Iron ? Yum yum...
It's time for something drastic. I'm sick of fighting with this tank. I just go to the other room and admire my 60g... Any thoughts on cleansing this nusiance from the live rock...I read about a week or two in a tub with tank water and maracyn in the dark...?
Help me....