Cyano harmful if eaten?

ladayen

I cleaned out one of my filters a bit today and some cyano bacteria that was growing in it fell into the tank. The fish swarmed all over it. Anything to worry about?

Byron

No. They must be starving; I've not heard of any fish eating cyanobacteria before.

sidluckman

In the world of SW, Koran angels are known to snack on cyano. I have noticed some of my other fish sampling it when I scrape it from aquarium glass, but they seem to do this out of reflex more than authentic hunger.

Some forms of cyano can be deadly dangerous, however, and here in Illinois this summer a number of dogs that had been allowed to play in a cyano infested pond suffered horrible consequences. Two died outright and two were hospitalized and largely paralyzed. Never heard the final outcome of this. Cyano can produce chemicals that are dangerous, so take care when working in tanks with cyano. No short-cuts like starting your siphon by mouth!

FWIW, I do not know if cyano or its by-products are lethal to fish, but it wouldn't surprise me. Fish die off in summer waterways for reasons such as high temperatures and low oxygen. It would not surprise me if cyano kills some as well.