Help!!

I have hair algae in my 55 gal planted tank. It's been up for 5 years,
filled with crypts, swords, anubias, hygros, water sprite, and many
others. I use 4 55 watt PC's 6400 K on for 12 hr.., CO2, 50 % monthly
water changes, and weekly Fe/K supplements. I have 4 SAE and 6 Amano
shrimps (anyone know of an online source for Amano's?). Fish are
Rainbowfish. My other tank uses the exact same everything except for
having tetras, and has NO algae......Any and all suggestions are
appreciated.

Dave