GFO causes algae outbreak?

Just started running a GFO and I had a major brown algae outbreak. It's the only thing I have changed in the past couple of weeks.

 

It's possible if your tank was iron limited and there is some dust getting into your system. Make sure the flow is slow i.e. < 100gph through the reactor. There is no grinding of the media, and make sure the media is well rinsed. Regardless, if your you sufficient amounts and phosphate lower, as desired, excess iron shouldn't matter.

 

I started to use it and had the same problem about 4 months ago I think I had too much flow and was grinding the gfo in my reactor so I turned it way down to where I can't see any flow . I was not sure if it was gfo dust or diatoms? but give it some time when your changing something with the water are you using ro/di water ? if not you could be seeing a diatom out break more than any thing it's just product dust.