nutrients expelled??

[WaterLogged]

Morning all, happy Monday.

I've been having a cyanno problem for a while now, and have tried many things. I have nothing in the tank that really needs light at the moment, so this weekend I left the lights off the whole time. When I got home the problem was way better, as it should be. My question was; when you kill the cyanno like that does it release nutrients back into the water column?

Thanks,
Mark