I does no3po4-x, great stuff. I have been slowly weening my system off the stuff and it's been holding up. We moved and had to transfer everything and this caused sand to stir and brought on the standard algae bloom. I'm down to around 3 ml once a week halfway between my water changes and it keeps everything in line.
+1 on the skimmer going nuts, it makes mine pull crap out of crystal clear water.
On a side note, a Red Sea rep happened to be at my lfs
one day and I asked him about it. He mentioned if your cal or especially alk
isn't in good parameters, it will cloud your tank. Also keep an eye on your ph as he said it could drop it slightly if your just starting out dosing it.
I read too that if your no3
aren't both high, it won't work well. It helps pull both organic and inorganic phosphate so that's a big Benefit from it. I've had good progress but it gets expensive which is why I am trying to ween it from the tank.