Oooooo . . . cle-VER! A turkey baster to get Polyquat right up close and personal inside the nasty parts of the steps.

So with that pad, are you saying there were no algae UNDER it? Just ON it? We recently put an old yoga mat under our steps. They take a serious beating by the dogs launching off them which has worn a dent into the sand under the corners. I've been wondering whather algeae will grow on and under the pad . . .