GFO does help with silicates. However, that help mostly depends on how you are setting up this tank. Sometimes speeding up nature isn't always a good thing. Things need to happen to make sure you have a strong bacterial foundation. If for some reason you have diatoms growing into the 4th month or so, I think GFO would help. Until then, the diatoms will provide food for your clean up crew and the copepods and amphipods. To add, you'll need some nutrients(no3 and po4) in the water column for your corals to thrive.