how can I get rid of my pea soup?!?

[kootenayreefer]

My reef aquarium is only about 3.5 months established and in it I have 3 chromis, a clown fish, a blue velvet damsel, a hermit crab, a few small pieces of live rock, and a plant of which I do not know the name. Up until about 3 weeks ago things seemed great then one day the water became cloudy, a day later the entire tank(50 gal) was completely green, I could not see anything. Unfortunately the local pet store advised me to do a water change, saying they had never heard of green water in a marine tank. After the partial water change things seemed worse, and now after having done some investigation I know that I should not have done this. I have called around, read through the posts here and realized I should check my phosphates, they were sky high, so I got some greenx and put that in my filter. Things have begun to clear up a little, however as you can see by my pic, things are still pretty bad. My question is, is there any way to get get the algae out of the water? I'm dying to look into my aquarium again, haven't seen my live rock for three weeks.
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