Welcome to my world ! I'm just starting to see some improvement. I too have had a "browm-type" hair algae taking over my 90g. My feeding has been drastically reduced as I appear to have beaten a parasite problem. Heavy feeding can be a big source of nutrients if not accompanied by heavy skimming. Right Bob...?
I'm pretty sure the culprit was aging bulbs. I replaced my 18 month old
ops: PC's last month and the algae is now "bleaching" and falling off the rocks. The fish are also grazing more as I'm feeding less. I have a Damsel that has a constant "trail of poorly processed algae" coming out of his...well, you know
. Very attractive !
I've made a lot of changes that have perhaps helped;
-Increased Actinic output
-dosing kalk
-reduce lighting cycle
Some other considerations ? -GAC, quality and "age". It will leach nutrients initially removed when it becomes "saturated".
-Daily replacement of "mechanical filtration" material. Get the "crap" out before it is converted into a nutrient.
Nitrates, phosphates/silicates, lighting...?