Hi MHG,
I may be able to help. First, I do have a question about the algae. Is the hair algae dense and thick green algae, or is it thin short hair algae? I only ask because I experienced short thin hair algae in my zeo system when I took my phates and trates to a unhealthy 0/0 level for too long. It wan't until I added some phosphate and nitrate that the algae went away. Here is a interesting paragraph from the neo zeo guide that may be of some interest too you:
"One of the complaints often voiced by some aquarists using this method is that a
short, brownish film forms on static surfaces (as previously mentioned, it is most
prominent on aquarium panes and less so on live rock and sand) that detracts from
the overall appearance of what would otherwise be a “pristine” display. Ironically, the
film seems to be directly related to insufficient phosphate being present in the system.
The current theory, based on research recently presented in Nature, is that
cyanobacteria in phosphate-limited ecosystems can shift from the utilization of
phosphorus to sulfur and/or nitrogen compounds in their cellular tissue. Of greater
importance, in our opinion, is that in many cases the appearance of brown
cyanobacteria is an indication that the phosphate concentration in the system is too
low for long-term survival of corals."
This is my best guess without seeing an actual picture of the algae in the tank.
Warmest Regards,
James