I just started last week. I have been dosing Pro Bio S and -Np from AF while running GFO.
My nitrates and phophates are always zero, and my coral coloration has been affected.
I figured feeding the reef roids and polyp booster would be a good way to help bump my nitrates up a little. First I shut off my return pump and put my tunze on a low speed. Add a few drops of PolypBooster. This is supposed to trigger all of your corals to go into feeding mode. After a few minutes, I the rest of my pumps off, mix about 1/8 tsp to about 25mL of tank water. Then I target feed using a 5mL syringe with a bent needle tip (the one that came with my bottle of aptasia x)
I have been target feeding my few mini zoanthid colonies, and there are mixed results. My red people eaters, king midas and rastas definitely show a feeding response. I have some others that don't seem as interested. I only have a few SPS corals, but they are all fat and happy, and have exhibited better polp extension since I have started feeding reef roids. My Mushrooms, rhodactis and ricordea all seem to love the reef roids.
I have a few brain corals and anemones that go crazy with a few drops of PolypBooster. They are are showing a feeding response to the reef roids, but I don't know if they are able to get anything. I might start mixing in some meatier foods like Mysis for when I feel my LPS and Nems.
Positive results so far, but I haven't been using it long enough to comment on nutrient build up or growth.