Well... what really happens is that the algae "fixes" the nutrients and does help eliminate them from the water column, but... it is just tricking the tests. You then have to get rid of the hair algae or whatever for "true" elimination of the waste.

Yes, Diatom blooms and other "cycle" issues typically signify your nearing the end of a cycle, but it is not "the end".

FWIW.. I have BIG hair algae problems in my seahorse tank right now, as a result of the death of a bunch of large turbo snails while I was away. I'm winning the battle, but slowly, and my tank has been "cycled" for a year plus.

D