Can Cyano Kill Fish?

It can & will kill corals, fish & inverts! ... Then, physically remove the cyano (do not stir it up or try to net it out as this just breaks it up & further disperses it in your tank) by siphoning it out & turn off your lights for 3 days (your corals will be fine).

Do fish eat cyanobacteria?

Unlike brown algae, cyanobacteria are not eaten by plecostomus and other algae eating fish. So, do not count on these fish to help clean up your blue-green algae problem.

How do you get rid of cyano?

One clever trick for daily siphoning of cyano is to run the siphon through a filter sock and keep the water you remove. The filter sock will trap the Cyano and allow clean water to pass through which can then be put back into your aquarium.