Place a power head or the return closer to the top of the water line so it creates a small vortex that will suck the stiff back into the water where your skimmer has a better chance to get it out. Also I used to Getty three same stuff in a freshwater tank. I positioned my return spray bar do that it was above the water line and that got rid of it too.
take a shot glass hold it between your fingers
put it into the center of the tank just till the water starts slowly flowing in remove it just before it fills to the top it will act like a mini skimmer