Brother reefers from Singapore, let me share you with my experience.
Recently when I was abroad my wife gave "little" extra calcium to my tank and there was a calcium shock which killed some of my corals,
all the fish and critters. After that came the aglae problem.
It started growing like wild fire. To make the matters worse, my wife kept feeding the tank (additives) and kept on feeding whts left. (most of the corals survive though)
When I returned home (after three months), most of my base rocks and sand and some of my corals were taken over by hair algae.
First thing I did was to brush the algae inside the aquarium (MY BIGGEST MISTAKE). Without knowing I introduce more algae!!!
The SOLUTION.
1. I introduced lots of hermit crabs, about 50 of them. (all of them were totally free for me as Im from Maldives)
2. Introduced a very common blenny.(Lawnmower Blenny - Salarias fasciatus)
3. Reduced the tempreture to 25 degrees Celsius
4. Stop feeding additives and food
5. Reduced lightings and light hours for 5hrs
6. Did LOTS of water changes.
7. WAITED for the nature to control.
As soon as I introduced the hermit crabs, they started their work and they controlled pretty much algae. But I noticed the long hair algae were not touched.
HERE COMES the BEST PART and I bet none of you guys would believe this. But it worked for me.
I introduced 4 Saron shrimps. YESS Saron Shrimps.
I haven't read any thing positive about this fellow.
But it really worked. The Saron Shrimps started eating the long hair algae. Trust me, though some reefers talk bad about this shrimp, its not what its labelled as. These fellows come out at night and nip off the hair algae and eat em pretty fast. And now Im totally free of algae. Now I respect these creatures more every day as they are my saviours.
Patience is all you need.