In the past we had a water supply issue right after I topped my pool off on opening. I shocked, pool turned brown.

Ran to pool store, they said water plant had a problem and loads of iron in the water. Gave me some things called Ferr-tabs (sp?). Said to put them in the skimmer, leave the pump running and they would cause metal to bond together and fall out of solution and gather in front of my return the next day.

Lo and behold they worked just as advertised. Issue resolved.

A few years ago I was using a copper algaecide, got the blonde hair green result, replaced a bunch of water and quit using the algaecide. Half way through the next year I found this place and started using bleach, and bought some Clorox Ultra, the new stuff with the added chemical that apparantly is some sort of metal sequesterant. The next day I had small piles of brown stuff in front of my return. Looked exactly like when I used ferr-tabs, but smaller quantities.

Do everything you can to get the metal out, don't add any and the green hair will go stop. Well, once you get it back to blonde, anyway