How to get rid of green hairy alage

[balajeek15]

I know it was started to grow in my tank few weeks ago when i did the maintenance, now yesterday when i actually turned on full light (usually mine are dark blue all time) i could notice the worst green hairy alage all over the rocks (1" long), many covering some portions of SPS, many on other soft corals around the base, i used my fingers to pull it off first as much i can, then used toothbrush to scrap (knocked/broke few sps's), it took the whole day yesterday. Even after that its not completely clean, they are still in many unreachable parts of the tank. a month ago i got about 10 different snail varieties as recommend here in R2R, those never come to rocks, they always come to glass only. I have two 2" size snails they always clean on back glass only.

Why is hair alage bloom in my tank in (i would say two months)? and its going strong.
What can i do to clear this quickly so i can save all the corals.

My tank is 71 gal DT from RedSea.
All tank parameters are in range.

Any advice would be really appreciated. Thanks.

 

[zukihara]

Try dosing phyto. Should work in a week or two.

 

[Duffer]

in order for algae to grow it needs nutrients, which means high phosphates. You say in line but most likely your phosphates are a false reading as the algae is feeding off of them. try lowering them but keep an eye on the phosphates. Manually pull what you can. I got a urchin also and it wiped the algae out.