There is the fact that many of the life forms that hitch hike on the algae may not make it through the more toxic portion of the cycle, but even as tough as Cheato is, it can go brittle and die off if parameters are off by too much. I'd wait until the Nitrites begin to drop and the Nitrates begin to rise, this should help to speed up that portion of the cycle and be much safer for all life within the system.
And it is pronounced; Key-toe-morph-ah.