I don't believe algae scrubbers grow micro algae. My algae scrubber grows ulva (Enteromorpha). It appeared naturally (unseeded)I'm curious with a turf scrubber if it releases spores or micro algae into the tank.
I can't be sure which type exactly.
But it doesn't spread to the display, if that's what your thinking. The display algae disappeared a short while after the scrubber matured.
I sometimes put the scrubber's screen into the display so the fish can eat the ulva. The algae still doesn't take up in the display.

. HOPEFULLY this won't be a hundred pages of never ending cycle of disagreement 



